In March 1650, as the soon-to-be-condemned Eusebius Andrewes rightly later noted, MPs changed martial law's name, but authorized its nature. They did so in order to try royalist conspirators like Andrewes for treason by procedures that did not bypass law, but did bypass juries that might nullify verdicts.Footnote ² They changed the name out of embarrassment; for in authorizing the court, these MPs overturned restrictions made by MPs during the Petition of Right Parliament of 1628, who had sought to ban such tribunals from operating in England during states of peace. Indeed, the High Court was more controversial in certain respects than the parliamentary courts-martial of the Civil War—which were also controversial—because it often sat during times when no enemy army was in the field in England. Instead of only existing in wartime, the High Court was authorized by MPs and their allies for “the preservation of the Common Peace, and for the better preventing of the miseries of a new and bloody War.”Footnote ³ The High Court of Justice would maintain the peace that common law courts could not maintain, so some in the government believed, through the terror inspired by the exemplary justice meted out on conspirators.Footnote ⁴

The High Court of Justice of 1650 and later iterations of the court have never received much attention. Scholars of the law have dismissed the courts as by-products of a supposedly arbitrary military regime.Footnote ⁵ Political historians of the period have in general agreed with this assessment. The High Courts have most often been used to gauge the despotism, or lack thereof, of the Commonwealth and Protectorate governments. The High Courts of Justice in these readings were brief and unfortunate aberrations in the longer history of English law.Footnote ⁶ How the High Court was made, or its relationship to other English courts, has not been thoroughly examined.

Yet while in some ways unique, the High Courts of Justice were located at one of the central intersections of law and politics in early modern England: who controlled discretion within the legal system. Indeed, in many ways, the creation of the High Courts of Justice was simply another instance of the central government attempting to control those who determined verdicts.Footnote ⁷ This desire was particularly strong in times and in areas of acute political, military, or economic distress. Here state officers often desired to remove discretion from juries so that they might better predict verdicts and more swiftly convict defendants whose actions, so it was believed, had seriously threatened stability.Footnote ⁸ Sometimes in these instances, the state used martial law. This was no less true of a parliamentary-controlled state. Indeed, what the 1640s and 1650s reveals is that parliaments as well as privy councils could find the bypassing of juries enticing.

In this article, we will examine these politics of procedure during the English Civil War and Interregnum. They will take us from the summer of 1643 through the tumultuous year of 1649, and, finally, through the periods of the Commonwealth and Protectorate. In the Civil War, parliament through ordinance and then through statute periodically legalized garrison courts martial to try traitors to the war effort—an adapted martial law jurisdiction.Footnote ⁹ In 1649, a hybrid tribunal that used councilors (not juries, and certainly not the House of Lords) called the “High Court of Justice” tried Charles I, and one month later five other royalists, for treason. The High Courts of Justice of the 1650s were made from the procedures of these tribunals. These hybrid tribunals were enormously controversial, but not arbitrary. This is not to say the High Courts of Justice were fair: they were not. Nevertheless, the state gathered extensive amounts of evidence for many of these trials, and commissioners of the High Court felt obliged to follow stated procedures. In making this hidden martial law jurisdiction, parliament overturned the restrictions placed upon martial law jurisdiction by the 1628 Parliament. But before we go any further, let us first recover early modern martial law's nature: its procedures, substantive laws, and its jurisdiction.

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Martial law is the estranged cousin of common law. As is the case for most black sheep, its family members view it with contempt. Mostly, it has been ignored. The literature on martial law in the early modern period is scandalously scarce in spite of the fact that its jurisdiction produced intense debates in the parliaments of the 1620s, 1640s, and 1680s. When scholars have studied martial law, they have generally done so through the lens of intellectual histories of common lawyers like John Selden and Sir Edward Coke, who opposed its use in England in peacetime in the 1620s.Footnote ¹⁰ Otherwise, only military scholars have studied martial law. And while useful, they have not explored martial law's relationship with England's other laws.Footnote ¹¹

The neglect of martial law by legal scholars can be traced to the scholarship of the great seventeenth-century jurist Sir Matthew Hale, who argued that martial law was “not a law at all . . . but something rather indulged than allowed as a law.”Footnote ¹² English legal historians have largely taken their cue from Hale, including their most recent assessment of martial law in the medieval and early modern period.Footnote ¹³ By the twentieth century, scholars working on martial law began calling for a change in the name of the concept, arguing that martial rule was a better description of martial law's nature. Martial law by the nineteenth century was the military rule over a civilian population.Footnote ¹⁴

In making these claims, nineteenth-century jurists argued that martial law was conceptually distinct from military law—a complementary form of law authorized by the Mutiny Acts to discipline soldiers. But there was no military law in England in the seventeenth century. While one could find a quotation or two that discussed “military discipline” or “military law,” no one in the seventeenth century— including Hale—would have made a jurisdictional distinction between martial law and military law. The procedures and substantive law of martial law could govern soldiers, cases of treason, and a variety of other potential wrongs.

Martial law in the early modern period was not military rule over a civilian population. Instead, it was a collection of practices and procedures. What precisely these procedures were depended on when and where Crown officers used martial law. However, generally, in England by the middle of the seventeenth century, martial law allowed judges to proceed by written information or plaints in cases of life and limb in lieu of an indictment by a grand jury, and to try suspects by a council of war instead of by a petty jury. A court martial decided cases on a plurality of votes, with the president either getting a double vote or the deciding vote if the council was deadlocked. The lead attorney of the court was often a civil lawyer, the judge advocate general, who had the joint responsibilities of facilitator and detective.Footnote ¹⁵ Witnesses and confessions were the two primary forms of proof. While associated with war, martial law was in fact defined as an alternative to common law for trying wrongs, including misdemeanors, felonies, and—most importantly for our purposes—treasons.

Courts martial were summary jurisdictions. A summary jurisdiction has come to be known in the English legal universe as a tribunal that avoided the formality of the common law and, in particular, use of grand and petty juries. Courts martial could certainly sustain this view. But summary procedure, when it was made in the Middle Ages, referred generally to procedural expediency. It had been adopted due to the often cumbersome rules of Roman canon law courts. According to R. H. Helmholz, the historian of ecclesiastical jurisdiction in England, in summary procedure, “all the formal steps that were not essential for the doing of justice could be omitted.”Footnote ¹⁶ Therefore, in most courts martial, witnesses were not deposed viva voce; but in some, they were. The court needed to hear all the evidence and determine its validity. But it had enormous discretion about the manner in which it did so.

The substantive laws of martial law were often but not always the printed ordinances or articles of war. The ordinances of war have a long history. All European nations by the seventeenth century used the articles of war, and the English were deeply influenced by Spanish, Dutch, and Swedish versions.Footnote ¹⁷ Most compared the army to an urban corporation or to a state, and just as a state needed law for the maintenance of order, so too did an army. These ordinances included a section on treason or traitorous offences, which Matthew Sutcliffe in his 1593 treatise on all things related to war had labeled “for the safety of the state, armie, or garrison.”Footnote ¹⁸ Specific acts included deserting to the side of the enemy, the delivering of a town to an enemy, furnishing the enemy with information or supplies, inciting an enemy to declare war, and breaking an exile. By the Civil War, these laws were included in the articles of war. The third Earl of Essex included them in 1642 in his category, “Of Duties in General.”Footnote ¹⁹

There were two perceived advantages to martial law. First, Crown jurists avoided juries. In areas of tumult, where juries might nullify verdicts, martial law served as a useful alternative. Second, commanders appreciated martial law because it was theoretically swifter and more brutal than common law. A soldier caught stealing or deserting would be tried immediately by a court martial and, if convicted, would die quickly for his offense.Footnote ²⁰ The goal of this severity was to terrify other soldiers into obedience. Those seeking to maintain order among the unruly and potentially dangerous often thought martial law to be the best form of law. Because it was so useful, from the early sixteenth century until the 1640s, Crown officers used martial law at various times to try rebels, soldiers, sailors, colonists in Jamestown, vagrants, known criminals, illegal retainers in Ireland, and rioters.Footnote ²¹

The use of these procedures was not without controversy. Indeed, in many of the areas where martial law was used, protests erupted over its supposed illegality.Footnote ²² The most famous, and the ones that by far made the most impact on the future of martial law jurisdiction, were the debates over martial law in 1628, where MPs investigated the commissions issued by James I and then Charles I from 1624 through the spring of 1628 in order to discipline soldiers stationed in the south of England. These debates, which also examined billeting, imprisonment, and the so-called “forced loan,” culminated in the Petition of Right.Footnote ²³

Jurists in the 1628 Parliament attempted to restrain martial law temporally. The Petition of Right asked that no man be punished by life or limb except by the laws of the land and that he be tried by his peers.Footnote ²⁴ But it was not so simple as just saying that martial law was illegal. Jurists recognized that the monarchy had always used a military jurisdiction during war. However, there were no agreements about what constituted wartime. Some, most notably Sir Edward Coke, believed that a state of war existed only when the Courts of Westminster were closed. Most lawyers in the Caroline period, however, argued that martial law could be used in armed camps in states of war defined by the presence of an enemy army with its banner raised. Everyone agreed that martial law could also be applied to enemies within the realm.Footnote ²⁵

None of these interpretations, while made in parliament, were concerned with parliaments. The MPs in 1628 were concerned with defining an inchoate jurisdiction. They were not concerned with granting martial law jurisdiction to future parliaments. Indeed, how parliament's lawmaking power related to the 1628 debates prior to the Civil War was unclear. This was more than sensible: after all, as everyone knew in 1628, the king controlled the armed forces. This truism was only shattered during the 1640s.

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The challenges of prosecuting a war led to innovations in law. These were often painfully made. And they only came after tense negotiations within the House of Commons, between representatives of the City of London and the House of Commons, and between the Commons and the House of Lords.Footnote ²⁶ During these negotiations, martial law bills were delayed, re-made through compromises, and sometimes failed to pass at all. From 1643 through 1646, parliament experimented with martial law in its garrison towns to try its own soldiers and others—civilian or soldier—who attempted to betray parliamentary garrisons. The garrison court martial was the end product: a martial law jurisdiction that reflected the institution that created it.

It was decided early on in the Civil War that the opposing sides would treat prisoners not as rebels—either against parliament or against the king—but as enemies who should be treated as prisoners of war.Footnote ²⁷ This classificatory scheme was meant to save lives. But it also meant that civilians who committed wrongs according either to the articles of war of the army or to the unwritten laws of war could be subject to martial law. In certain cases that involved spying or involving conspiracies to overthrow garrisons, both Charles I and parliament resorted to trying suspects at martial law.Footnote ²⁸ Death by martial law, so both sides hoped, might convince potential future conspirators to remain quiet.

Parliament began experimenting with martial law to try treason in the spring of 1643. One of the first cases came when Nathanial Fiennes, the governor of Bristol, discovered a plot made by prominent citizens to overthrow the town and hand it over to the king.Footnote ²⁹ On 20 May, a council of war condemned the two principal leaders to death and promised to investigate other potential conspirators.Footnote ³⁰ Before acting, Fiennes appealed to parliament for approval. On 22 May, parliament allowed the council of war to execute the ringleaders, and three days later, it published an explanation for doing so.Footnote ³¹ The council of war convicted them of “traitorous intelligence” with the enemy and of a “traitorous conspiracy” to overthrow the garrison at Bristol.Footnote ³² Civilians were now subject to martial law for certain types of treason.

A similar case arose less than a month later in London. But in this case, those in opposition to martial law attempted to prevent the work done by the Parliament of 1628 from being destroyed by the Parliament of 1643. On the last day of May, John Pym made public a plot by the MP Edmund Waller and several prominent London citizens to take the City for the king.Footnote ³³ Pym wanted the conspirators tried by martial law. Sir Simonds D'Ewes opposed Pym and made the factually inaccurate claim that “martial law . . . was in former ages utterly unknowne to the subjects of England.”Footnote ³⁴ In order to quiet doubters, supporters of martial law brought in Isaac Dorislaus, a learned Dutch civil lawyer and the judge advocate general of Essex's army. He reassured the Commons that trying conspirators by martial law was common amongst all armies during times of war. D'Ewes's disgust towards martial law, John Pym, and the “fiery spirits,” is evident in his journal: “this made divers to dislike the proceedings more than formerly seeing that the lives of men were to be taken away upon an advocates opinions being also of Holland.”Footnote ³⁵ Others were appeased. Six men ultimately came before a court martial on 30 June. A London council of war publicly executed two of them.Footnote ³⁶

The use of martial law remained controversial. By 1644, many allied to the parliamentary cause wanted to establish a sitting court martial in London to try traitors and others who had committed offences relating to war. The problem was that the Lord General of the army, Essex, had exclusive martial law jurisdiction over his soldiers. Indeed, he had provided parliament commissions to try the Waller conspirators in 1643.Footnote ³⁷ This arrangement became strained in the autumn of 1643 when several notable parliamentary commanders defected to Charles I, including Sir John Hotham and his son, and Sir Alexander Carew.Footnote ³⁸ Twice in the fall of 1643, the Commons requested that Essex grant a standing commission for a court martial in London to try offenders for treason and other military crimes. The Lord General, in typically petulant fashion, finally gave a commission in November 1643 that excluded any man serving under him from the commission's purview, effectively preventing parliament from trying the Hothams and Carew.Footnote ³⁹

The issue was not reopened until the following May, when members of the London government, concerned about both spies and traitors, pressed for a sitting court martial. Their demands led parliament to assign a committee to draft a bill for a sitting court martial in London.Footnote ⁴⁰ The bill was hotly contested; according to the diarist Laurence Whitaker, the bill “was twice read & committed: it being debated bec: it was to establish martiall law, wch in ye Peticon of Right had been cryed down.”Footnote ⁴¹ It was only revived in July after the City of London made another petition for a court to try delinquents.Footnote ⁴² However, the Lords held the bill up for over a month. They were concerned about how both houses could supervise the tribunal, desiring that parliament could provide mercy for those convicted at martial law.Footnote ⁴³ After several debates, and further interventions by the City of London, the bill passed without the Lords’ provision on 16 August.Footnote ⁴⁴ The court's existence was limited to four months.

Parliament adopted seven ordinances of war for the court martial in London, which had jurisdiction to try “all such cases as belong to Military Cognizance, according to the Articles in this present Ordinance mentioned.”Footnote ⁴⁵ The articles were taken from Sutcliffe's category “for the safety of the state, armie, or garrison.”Footnote ⁴⁶ These ordinances were as follows: no person, either soldier or civilian, shall go from a place under the power of parliament to the king or queen or give any intelligence to an officer of the king; no person shall plot to betray or in fact betray a parliamentary garrison; no person may relieve an enemy with money or victuals; no officer shall make mutinous assemblies; no guardian shall suffer a prisoner of war to escape; no person shall take up arms against parliament after having taken the national covenant; and no officer shall desert his trust and adhere to the enemy. Six of the seven articles could carry the penalty of death.Footnote ⁴⁷

The London court martial sat through the end of December 1644.Footnote ⁴⁸ While it sat, it focused on those who had betrayed the parliamentary war effort. It tried Hotham, his son, and Alexander Carew, as well as Thomas Syppens and Francis Pitts, for conspiring with the king to take parliamentary garrisons. By November, it was authorized to try all deserters.Footnote ⁴⁹ In December, the Lords attempted to save Hotham's life and failed. He was executed on 2 January. The Lords’ dismay at his death led to a concerted effort by the upper house to prevent any further court martial from sitting in London.Footnote ⁵⁰ With the exception of a court martial that sat in Kent to try royalist rebels from April 1645 through the end of the year, no court martial was authorized to prosecute civilians until the spring of 1646.Footnote ⁵¹

In January 1646, the Commons once again pushed for a sitting court martial in various parliamentary garrisons, this time to try royalist spies.Footnote ⁵² This variation included an amendment that refused any claims to exception, even for peers of the realm. The Lords refused and intense debates between the two houses continued through March. Finally, the Commons relented and removed the amendment from each successive ordinance, ending with the London ordinance in April 1646. They perhaps did so because of their desire to try William Murray, an agent of Charles I, who had been caught coming into the country from France in February.Footnote ⁵³ Garrison courts martial, for the last time in the war, sat in London and in many other parliamentary garrisons throughout the summer of 1646.Footnote ⁵⁴ Like the court martial of 1644, it had seven ordinances taken from Sutcliffe's category for the “safety of the state, garrison, and army.” It also contained two additional articles related to spies and former royalists coming into parliamentary-controlled cities.Footnote ⁵⁵ But this court, unlike its predecessor, only had jurisdiction over wrongs committed in London. Murray's seems to be one of the few cases the court heard, and he was acquitted.Footnote ⁵⁶

Those prosecuting the war found the procedural components of martial law useful during the Civil War. Nevertheless, they made adaptations in martial law procedure.Footnote ⁵⁷ Let us examine them.

First, parliament designated allies to be commissioners in an attempt to control the discretion of the court. It was not unusual for civilians to serve on courts martial. Indeed, this had happened in the 1620s, when mayors, their deputies, and deputy lieutenants frequently served on courts martial.Footnote ⁵⁸ Parliament repeated this strategy from June 1643 onwards. Laurence Whitaker reported that members of the London militia, as well as military men, had been chosen to serve on the court martial of the Waller conspirators.Footnote ⁵⁹ Men closely associated with the London government continued to serve on garrison courts martial in 1644 and in 1646, including the lawyers John Bradshaw and William Steele.Footnote ⁶⁰ Alongside the London militia, parliament nominated high-ranking military officers. Many of these men also served in parliament. In 1644, parliament mandated that at least three of the commissioners on any court martial be members of both parliament and the army. By 1646, this proviso was impossible due to the Self-Denying Ordinance, and parliament settled on a mandate of notification before any execution could take place.Footnote ⁶¹ In both of these tribunals, parliament chose all of the potential commissioners, and listed them in the respective ordinance.

The second major innovation was that parliament opened the confrontation stage of the trial to the public as early as the summer of 1643. Mercurius Civicus reported that 4 October 1644 “was the first day of the publique sitting of the Court-martiall in Guildhall London, they having before sate at Weavers-hall, about the preparing of examinations, and other matters in readinesse for publique trial.”Footnote ⁶² The public confrontation stage of these courts martial went against the often private councils of war of English armies. William Prynne explained to the unimpressed Isaac Dorislaus the rationale for this innovation in an attempt to get him to open the court martial of Nathaniel Fiennes to the public, which was a traditional court martial conducted by the army: “that there was as great cause to give the Parliament, City, and kingdome satisfaction in this . . . it being of as like publike concernment.”Footnote ⁶³ Prynne also pointed out that all the courts of England were open to the public and that courts of war should be no different.

Third, the crafters of the garrison courts martial installed a quorum requirement. In all of the ordinances for a garrison court martial, with the sole exception of a draft ordinance for Hampshire in 1645, parliament named around fifty potential commissioners who could sit on the court, with twelve required to meet the quorum.Footnote ⁶⁴ While it had not been unusual to have twelve commissioners at a normal court martial, it was never necessary. Parliament had mandated a quorum of twelve men as early as 1643. Those who were drafting the orders for the court seemed to want to ensure that the magical number of twelve men sat on a court martial, the required number for a jury.Footnote ⁶⁵

All of the innovations made to the court martial—the sunset clauses, the public confrontation stage, the quorum, exemptions for peers, the allies on the court—were generated out of parliamentary practice. They were intended to meet the unique legal demands of the 1640s but also to accommodate those in opposition to the legalization of courts martial. At the same time, the end goals of the garrison court martial were the same as previous uses of martial law—to remove discretion into the hands of state officers, and through swift exemplary punishment of traitors generate obedience through terror.

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The High Court of Justice of 1650 was not the first High Court to sit in England.Footnote ⁶⁶ The tribunal that tried Charles went by the same name.Footnote ⁶⁷ And like later tribunals, the House of Commons designed the procedures in order to control judicial discretion. It seems likely that a court martial was one of the influences for what in the end would be a hybrid tribunal.Footnote ⁶⁸ However, the trial of Charles and the later trials of five of his commanders were different in several respects from either the garrison courts martial or from later High Courts of Justice. They were larger and grander, and the named commissioners were meant to represent the entire nation.Footnote ⁶⁹ They were much more chaotically constructed. They were not meant to be sitting tribunals, even for a limited amount of time. Most importantly, unlike the courts martial of the English Civil War or later High Courts of Justice, in both the prosecution of Charles and the five royalists in February the Commons used notoriety as a form of proof.

The key procedural component of the trial is in the first line of the Act authorizing the tribunal to try Charles:

Charles was guilty of treason, and this was “notorious.” Medieval English monarchs had utilized notoriety against so-called public enemies: criminals who were so well known and dangerous that their guilt was obvious. Notoriety could be used as a justification for detention, a means of bringing a suspect into court, or a declaration of that suspect's guilt.Footnote ⁷¹ The king could thus order the execution of the criminal without proving him guilty through eyewitnesses or through a confession. By the end of the fourteenth century, parliament had adopted this form of proof to convict suspects of treason by simple vote: what has come to be known as an act of attainder. As Clive Holmes has recognized, the House of Commons was probably borrowing from an act of attainder when it prepared the charge.Footnote ⁷² The Kingedome's Weekly Intelligencer, for example, reported that the Commons was preparing both an attainder and an ordinance for the trial of the king in December.Footnote ⁷³ Nevertheless—and this is what made the trial so odd—the Commons still desired to showcase other forms of proof for Charles's trial. In the end, the Court convicted Charles by his refusal to plea and due to “the Notoreity of the Matters of Fact charged upon him as aforesaid.”Footnote ⁷⁴

The Commons wanted to control discretion at the confrontation stage.Footnote ⁷⁵ Naturally, the novelty of the trial generated problems. The Commons needed to place discretion in the hands of men who would follow through with the Commons’ plan. Which procedures could the Commons use? An ordinary jury trial was out of the question because it would have lacked enough gravity for the momentous occasion. A great jury trial, filled with the most loyal and prominent men, was initially conceived. Unfortunately, we know little about how the judges deliberated.Footnote ⁷⁶ There is evidence to suggest that the Commons contemplated the idea of impeachment which involved the parliament trying one of the king's ministers for corruption or even treason.Footnote ⁷⁷ Indeed, Charles, according to the charge, had overstepped his bounds as king, abused his power, and therefore had committed treason. John Cooke concluded the charge against Charles by stating the “said people of England impeach the said Charles Stuart, as a Tyrant Traytor Murderer and a Publick and implacable Enemy to the Commonwealth of England.”Footnote ⁷⁸ However, the procedures of the impeachment trial gave all discretion, both in law and in fact, to the House of Lords, a body that even before it refused to pass the bill that authorized the trial of the king was known to be far more conservative than the Commons. Impeachment procedures were not suitable for the occasion. The Commons also considered trying Charles by a court martial.Footnote ⁷⁹

Indeed, some of the procedures of the trial were consistent with a court martial. By 10 January, it was decided that a presidency council of judges, aided by four legal assistants, and led by John Bradshaw, a lawyer connected to the London government, would preside over the court.Footnote ⁸⁰ This court had an enormous amount of discretion in how it would take evidence. The court was allowed to take evidence from witnesses either live, viva voce, or by written deposition.Footnote ⁸¹ It was thus a summary tribunal: it had a mandate to hear evidence, but it had enormous discretion as to the rules in which that evidence was to be taken. In the end, the court decided upon a confrontation process that mirrored many continental courts: it took written depositions and then had each deponent testify upon oath that their testimony was true.Footnote ⁸² There was no distinction between triers of law and triers of fact: the High Court judged both.Footnote ⁸³ Army members and Isaac Dorislaus participated as commissioners and as council. The similarities between a court martial and the High Court of Justice did not go unnoticed.Footnote ⁸⁴ Charles's trial, however, was much too muddled and extraordinary to provide a model for the High Courts of Justice of the 1650s. Indeed, the later courts never used notoriety to convict defendants. The quorum requirement of twenty was also higher than either the 1640s courts martial or later iterations of the High Court of Justice.

The High Court was called into action quickly after the execution of Charles to hear and determine treason cases against five royalist leaders of the Second Civil War.Footnote ⁸⁵ The earls of Cambridge, Norwich, and Holland, as well as Lord Arthur Capel and Sir John Owen had earned the enmity of the army for their leading roles in the conflict.Footnote ⁸⁶ As in the case for Charles, parliament had considered a variety of different legal mechanisms to punish them. As early as September 1648, the House of Commons had advocated for the attainder of the Earl of Norwich and the impeachment of Lord Capel, the former leaders of the Royalists at Colchester. Capel was duly impeached but not tried for his life in October. Meanwhile in November, the Commons considered banishing the earls of Holland, Norwich, Sir Henry Owen, and Capel, as well as two others.Footnote ⁸⁷ This leniency ended with the Purge. Eventually, the Commons decided to try them by a High Court of Justice.Footnote ⁸⁸

In many ways, the trials of the five men contained the same hybrid procedural devices found in Charles's trial. While the Commons had not decided in the end to utilize attainder, proof by notoriety was an important device for the prosecution in these cases. The Attorney General, William Steele, argued on 9 February for the “notoriousness of the facts” on the first day of the confrontation stage of the trial for the earl of Cambridge.Footnote ⁸⁹ Like the trial for Charles, witnesses were also utilized. Similarly, a large body of commissioners—a quorum of fifteen was mandated—determined both fact and law. Close to fifty were present at the opening of the confrontation stage.Footnote ⁹⁰

However, this tribunal was just as much about jurisdictional politics as it was about procedural politics. The tribunal crafted by parliament was based on the Civil Power, which prevented the defendants from seeking protection at a martial law court as prisoners of war. Indeed, both Capel and Norwich had been granted that protection when they surrendered at Colchester. However, their surrender did not protect them from civil prosecution.Footnote ⁹¹ Capel became aware that the High Court, as a hybrid tribunal, offered him the worst of both worlds. He pleaded to be “wholly comprehended by the Martiall Law” that might honor his surrender agreement. Otherwise, he asked, after citing the Petition of Right, to “see his Jury” and to be tried by peers. That jury, he believed, might have mercy in store for him.Footnote ⁹² As he feared, the High Court of Justice, as a hybrid tribunal, proved to be a lethal concoction. He went to the scaffold on 9 March.Footnote ⁹³

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By the spring of 1650 there was still no peace. Fighting royalists and rebels in Ireland, the Commonwealth was preparing for a new war against its former ally, the Scots. Further, royalists still residing in England were plotting the restoration of the Stuart monarchy. Enemies were everywhere. New treason laws had been created that mandated obedience to the Commonwealth. In March 1650, the state considered legalizing martial law so that it could try several royalist conspirators that had recently been entrapped through the efforts of the Council of State.Footnote ⁹⁴ They renamed it a High Court of Justice.

There was no expectation that the High Courts would be reconstructed after 1649. But the treason trial of John Lilburne perhaps changed the Commonwealth's mind about using martial law. Since the regicide, John Lilburne, the leading “Leveller,” had consistently attacked the new government. Over the course of 1649, he published numerous attacks on Oliver Cromwell, the Rump Parliament, and the army. He accused Cromwell of treason, declared that the army had illegally purged parliament, and argued that the current government was a puppet to an arbitrary military power.Footnote ⁹⁵ The Commonwealth could not get Lilburne to shut up. It ordered Lilburne tried in London for treason according to recent acts that prohibited public polemical attacks against the government. In October, Lilburne was indicted by a grand jury. At his trial, Lilburne argued to the petty jury that it was a trier of law as well as fact, and that he was being tried by bad law. The jury agreed with Lilburne, and acquitted him.Footnote ⁹⁶ The Council of State was furious. It had been humiliated by a jury.

Its desire to authorize martial law the following March appears to have been a solution to the problems that arose in Lilburne's trial. On 14 March 1650, a bill was introduced entitled, “An Act for Establishing A Court Martial within the Cities of London and Westminster, and late lines of Communication.”Footnote ⁹⁷ We can tell from this title that the crafters of the bill looked to the garrison courts martial that had operated in London during the Civil War. The ordinance for the 1644 court martial, for example, was titled “Ordinance for the Establishment of Martial Law within the Cities of London and Westminster and the lines of communication.”Footnote ⁹⁸ Meanwhile, the ordinance for the 1646 court martial was titled, “Ordinance for the speedy establishment of a court martial within the Cities of London and Westminster and the Lines of Communication.”Footnote ⁹⁹ The change to the title of this new Act was minimal: too minimal, in fact. The Lines of Communication, the ringed fortresses built to protect London during the war, had largely been dismantled in 1647.Footnote ¹⁰⁰ The only reason why language relating to the Lines of Communication was included was because the makers of the bill were working from a template: the ordinances that legalized the courts martial in London during the Civil War.

After the first and second readings of the bill, parliament resolved to rename the court to “The High Court of Justice.”Footnote ¹⁰¹ Hidden behind this name, parliament eventually authorized a court martial to sit in London. In deliberations over the next twelve days, MPs inserted two amendments into the bill that altered the court's procedure. The first, passed on 21 March, ensured that the High Court of Justice in no way diminished the powers of the Commonwealth's generals and its admirals. We can see, even before reading the final version of the act, the close relationship between the High Court of Justice and martial law—so close that the Commons had to make sure the court would not interfere with the legal power of their generals. Second, on the same day, parliament passed an amendment that required all of the commissioners of the High Court of Justice to take an oath.Footnote ¹⁰² Most importantly, no amendments were passed that fundamentally changed the procedure of the court. Its name was changed, but its nature endured. The bill passed on 26 March.Footnote ¹⁰³

The new High Court was to be a summary jurisdiction. Like the 1649 courts, the High Court of Justice was given powers for “examination upon Oath (which the Court hath hereby authority to administer) or otherwise, and taking any other Evidence concerning the same.”Footnote ¹⁰⁴ The High Court of Justice needed to hear evidence when it prosecuted suspects. But the specific presentation of that evidence was left to the court's discretion. The discretion also extended to the making of the charges. The court had the power to “take order for the charging of Offenders with all or any of the Crimes . . . and for receiving their personal answer thereunto.”Footnote ¹⁰⁵ There would be no indictment by grand jury. Just as the judge advocate general usually generated the charge for courts martial, so too did the officers of the High Court of Justice.

There were other consistencies between the High Court of Justice of 1650 and the garrison courts martial of the Civil War. First, like the garrison courts martial, parliament nominated at least sixty-six commissioners and mandated twelve for a quorum. However, in the courts of the 1650s, almost no military men were nominated as judges. Instead, it would be legal officers of the state and members of London's loyal elite who were to act as commissioners. Parliament's allies sat on the tribunal. Second, in both times that the garrison court martial sat, in 1644 and 1646, parliament put a time stamp on its existence. In 1644, the court martial was initially authorized to sit for three months, and eventually sat for four. The 1646 court martial also sat for three months. Likewise the 1650 High Court of Justice was authorized to sit for six months, from March 1650 until the following September. The rationale for these limitations was also similar. Many within both the parliaments of the 1640s and the Parliament of 1650 were uncomfortable granting permanent jurisdiction. Third, like a court martial, the High Court of Justice would determine cases by plurality. The High Court of Justice could convict and punish “as the Said Commissioners or the major part of them then present shall judge to appertain to Justice.”Footnote ¹⁰⁶

In the Act, parliament dictated that the High Court could specifically try eight offences. The first seven articles were nearly identical to the first seven articles assigned to the garrison courts martial of the Civil War. The High Court of Justice could punish those who communicated with the “Royal Family”; those who plotted to betray any towns, garrisons, or anything “belonging to this Commonwealth”; those who harbored delinquents; those participating in mutinous assemblies; those who allowed prisoners of war to escape; those taking up arms against parliament; and those who deserted. The articles were thus also derived from the category of crimes labeled by Matthew Sutcliffe concerning “the safety of the state, garrison, and army.”Footnote ¹⁰⁷ The ordinance authorizing garrison courts martial during the Civil War weighed heavily on those who brought the 1650 High Court of Justice into being.

The key divergence between the act authorizing the 1650 High Court of Justice and the acts that authorized the garrison courts martial of the Civil War was the eighth article, which allowed the High Court to have cognizance over five Acts passed by parliament in 1649 that were related to treason.Footnote ¹⁰⁸ The first declared that anyone who declared Charles Stuart king was guilty of treason. Two others involved the making of scandalous pamphlets and removing “papists” and delinquents from London.Footnote ¹⁰⁹ The two most important treason acts reframed English treason law away from attacks on the king's personal body.Footnote ¹¹⁰ These made offences like attacks on the Council of State, or the clipping or counterfeiting of money, illegal. But they also included military crimes: mutiny in the army, conspiring with the Commonwealth's enemies, engaging in rebellion, and attempting to seize Commonwealth garrisons were included in both these acts. In other words, the first seven articles in the Act authorizing the High Court of Justice had already been enacted as treason the year before. Why, if parliament had already passed these articles into law, did it list the articles separately in the 1650 Act for Establishing a High Court of Justice?

These redundancies reveal the nature of the making of the Act itself. Those who crafted it started with the 1644 ordinance to establish a garrison court martial in London. They then made minor modifications throughout the text by adding a short new preface and changing the names of the commissioners, the name of the court, and the exact timeline for the court's sitting. They made minor modifications to the first seven articles. Then at the end, they inserted a clause that legalized the previous Acts relating to treason that parliament had made in 1649. The redundancies confirm that the templates of the Act establishing a High Court of Justice were the ordinances that authorized courts martial in London during the Civil War.

English citizens were not spared from these procedures. Indeed, the place of one's birth did not matter. Instead, the High Court of Justice had jurisdiction over any “Contrivers or Actors,” or more simply, “person or persons.”Footnote ¹¹¹ It was to be the act, and not the innate nature of the individual, that was to determine jurisdiction. In this Act, then, the Commonwealth not so much altered the subject/enemy distinction so much as it simply ignored it. Thus, like in the Civil War, one's birthplace did not give one the birthrights like trial by jury and due process normally associated with subjecthood. All could be enemies according to the statute that created the High Court of Justice.

The most famous case the court heard in the summer of 1650 was the treason trial of a former royalist colonel, Eusebius Andrewes. Andrewes had served Charles I through the surrender of Worcester in 1646. After the Second Civil War, Andrewes became ensnared in a ruse designed by the Commonwealth's Council of State to uncover potential royalist conspiracies. Andrewes had agreed to a conspiracy to take Ely for Charles Stuart. After tracking Andrewes for some time, the Council of State confronted him in the spring of 1650. A three person committee led by John Bradshaw, acting in his capacity as president of the Council of State, interrogated Andrewes, who subsequently delivered a written answer to the charge that he had attempted to subvert the government. Andrewes finally came before the court in August 1650, after several petitions he had written had been ignored.Footnote ¹¹² His prospects were not good. Not only did the court have all of Andrewes's correspondences about the plot to seize Ely, but it also had his own written answer, where Andrewes confessed to participating in the conspiracy, but that he was only “passively active.”Footnote ¹¹³ The initial answer seemed to be an attempt to induce mercy from a jury. But upon discovering how he was to be tried, Andrewes denied the validity of a court where he could expect no such mercy. He did so by calling upon his legal and military training. Andrewes was trained in the law. He had been admitted to Lincoln's Inn in 1620, and was called to the bar in 1627. Andrewes also had experience in war. He had served with the armies of Charles I, ending his career with the rank of colonel in 1646.Footnote ¹¹⁴ Andrewes used both of these knowledge bases to attack the court and its procedure.

Andrewes issued his written response, read by the court in August, which claimed:

He continued this line of attack when he came before the court. He admonished the commissioners to “remember the petition of Right.”Footnote ¹¹⁶ The Petition, according to Andrewes, had affirmed that trial involving life and death for Englishmen could only occur by the laws of the land. He argued that the martial commissioners were evil, not because of their personal qualities, but through “their proceedings by their own will and opinion, being themselves the Judges and Jury; offices incompatible and inconsistent with the people's liberties.” He argued that if the commissioners “read the Act by which you now sit, I am confident you will grant this power to be of the same nature, though not under the same name.”Footnote ¹¹⁷ The High Court, however, dismissed Andrewes's arguments that it was an illegal court martial and convicted him of treason, using his own initial confession.

The Commonwealth found the High Court of Justice useful. In the same summer that the High Court heard and determined Andrewes's case, the Commonwealth threatened to use the High Court of Justice to execute six imprisoned royalists as retribution for the murder of Anthony Ascham, the Commonwealth envoy to Spain. It ultimately decided not to execute the six men, holding them hostage as leverage for the safety of its overseas diplomats instead.Footnote ¹¹⁸ In December 1650, parliament authorized a High Court of Justice to sit in Norfolk to hear, determine, and punish those who had recently participated in a royalist rebellion, the so-called “winter rising,” where those sympathetic to Charles Stuart attempted to take Norwich for the exiled monarch. At least eighteen and up to thirty-four men were executed by the High Court of Justice in Norfolk.Footnote ¹¹⁹ The High Court continued to operate through 1651. In that summer, the court tried the Presbyterian minister Christopher Love, John Gibbons, and other London plotters who had been secretly conspiring with the Scots. The High Court of Justice tried “people or persons” who, by their actions, had become enemies of the state.Footnote ¹²⁰ At the High Courts of Justice, the Commonwealth was not embarrassed by juries.

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The Commonwealth did not last long. On 20 April 1653, Oliver Cromwell dissolved the Rump Parliament. A new one was called shortly thereafter. Cromwell thought little better of this one, the “Barebones Parliament.” The majority of members, after increased friction between moderates and radicals, resigned the powers that Cromwell had given them on 12 December. Several days later, Oliver Cromwell became “the Lord Protector of the Commonwealth, Scotland, and Ireland.”Footnote ¹²¹ Once again, a single man stood at the center of English government.

With this transformation in 1653 from a Commonwealth to a Protectorate, the new government made changes to the Commonwealth's treason laws.Footnote ¹²² In a protectoral ordinance passed in January 1654, Oliver Cromwell streamlined the treason acts of the Commonwealth period and incorporated articles of war related to treason fully into the ordinance.Footnote ¹²³ The ordinance also revived English statutory treason. Because the government once again revolved around the physical body of one man, it was now treason to “compass or imagine the death of the Lord Protector for the time being”—a clear aping of English statutory treason law, which stated it was treason to “compass or imagine the Death of our Lord the King.”Footnote ¹²⁴

English statutory treason would now be tried by martial law procedure. That spring a conspiracy had been hatched to murder Cromwell and overwhelm the Protector's garrisons in London.Footnote ¹²⁵ John Gerard, Peter Vowell, and Somerset Fox were accused of being part of a conspiracy to murder Cromwell as he traveled from London to Hampton Court on 13 May. Others were then to take control of garrisons in and around London and proclaim Charles Stuart king of England. The plot failed, and the plotters were captured. On 13 June, a protectoral ordinance authorized the sitting of a High Court of Justice through 20 August. This High Court of Justice had cognizance over all treasons and misprisions of treasons listed in the treason ordinance of January 1654.Footnote ¹²⁶

The authorizations of the High Courts of Justice were not without opposition. Already by 1653, there is circumstantial evidence that some members of parliament opposed the sitting of the High Court of Justice. In that parliament, the Council of State had recommended a bill on 10 August to legalize a High Court of Justice to punish potential conspirators working for Charles Stuart.Footnote ¹²⁷ But the bill was not introduced until almost the middle of October, and then it disappeared in committee. Finally on 21 November, the bill passed, but apparently many were upset with the speed at which the bill was passed through the Commons.Footnote ¹²⁸ John Lilburne, after all, had humiliated the state once again that summer, when there was no authorized High Court of Justice.Footnote ¹²⁹ Negotiations over the High Court's procedures continued throughout the period.

However, we should not overstate opposition to the High Court of Justice. Some scholars have argued that Cromwell's use of common law to try captured rebels in the immediate aftermath of Penruddock's rising—a royalist rebellion in Wiltshire in the spring of 1655—as evidence that the Protector favored the common law. There is no evidence to support this assertion. Instead, as Stephen Black has noted, he had no other option but to use common law.Footnote ¹³⁰ Under the terms of the Instrument of Government, the written constitution that established the Protectorate in December 1653, Cromwell could issue ordinances only until the meeting of the first Protectorate Parliament. Further, those ordinances would only remain lawful if parliament passed them as statutes. This power allowed Cromwell to issue the new treason ordinance in January 1654, and it allowed him to authorize a sitting of the High Court of Justice in the summer of 1654. But once the first Protectorate Parliament met in the fall of 1654, Cromwell could no longer make these ordinances. This contentious parliament did not pass a new Act for the sitting of a High Court of Justice.Footnote ¹³¹ Therefore, Cromwell had to try the rebels at the assizes.

When the next parliament met in the fall of 1656, Cromwell pressed for a new statute that would make it treason to compass the death of the Lord Protector, and one that authorized a sitting of a High Court of Justice. The bill was entitled, for the “Security of his Highness the Lord Protector.”Footnote ¹³² Cromwell and his spymaster John Thurloe were well aware that royalists and other disaffected persons continued to plot against the government. Indeed, there had been a plot, unbeknownst to the Protector, to take his life on the first day of parliament, 17 September 1656.Footnote ¹³³ After a second reading on 26 September, parliament passed the bill on 9 October. Some MPs had reservations about legalizing a new High Court of Justice but failed in an attempt to mandate that three judges had to participate to make a lawful quorum. The act authorized the Protector to call a High Court of Justice in England, Scotland, or Ireland by a commission of the Great Seal through the last sitting of the subsequent parliament.Footnote ¹³⁴

The Act both expanded and limited the powers of the High Court of Justice. It expanded the Court's powers of punishment. The High Court of Justice could now punish High Treason and misprision of treason by the full, traditional method of hanging, drawing and quartering. It was also explicitly authorized for the first time to take the property of traitors.Footnote ¹³⁵ But in other areas, parliament restricted the High Court's powers. The High Court only had powers over military treason, over those who imagined the death of the Protector, and over those who proclaimed Charles Stuart king. Its ability to punish those clipping coinage was no longer theoretically available. The quorum requirement was raised to seventeen and the commissioner pool was dramatically raised to at least 142 men, who once again represented the entire nation and not simply London. In terms of procedure, the Court only had powers to examine witnesses “upon oath . . . or upon confession.”Footnote ¹³⁶

Cromwell did not use this variation of the High Court of Justice until the summer of 1658. That spring, Thurloe had swept up a number of suspected royalist plotters. Sir Henry Slingsby, who had been in Hull, was entrapped by military officers pretending to want to give up the garrison to Charles Stuart. The second caught was Dr. John Hewitt, an Anglican minister and leader of a royalist network in London that had been planning an uprising. The third was John Mordaunt, the leader of the “new action party” in Surrey, which had also been involved in planning an uprising.Footnote ¹³⁷ Nine other plotters were tried that summer. Three were executed.

From the fall of 1658 through 1660, the non-monarchical governments of England did not use the High Court of Justice to punish treason. Cromwell died in September 1658. His son Richard was deposed as Protector in May 1659. The return of the rule of the Rump Parliament did not lead to the return of stability. In August 1659, parliament successfully put down “Booth's Rising” in Cheshire and Lancashire. The punitive measures parliament took were slight, and did not involve a High Court of Justice. It is not clear why. Perhaps, as David Underdown has suggested, the increased divisions between the army and parliament by the fall of 1659 prevented any decisive action.Footnote ¹³⁸ Charles II, restored in 1660, used common law to try the regicides.

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The Commonwealth and later the Protectorate used the High Court of Justice for two reasons: to terrify those thinking of committing treason into obedience, and for fear of jury nullification. They did not use the High Court of Justice to avoid the taking of evidence. Indeed, while critics—both contemporaries and subsequent historians—of the Commonwealth and Protectorate used the procedures of the High Court of Justice as grist for their mill, their charges that the High Court was arbitrary, and that conviction was predetermined, were not true. The High Court of Justice, while highly advantageous to the state, was not arbitrary.

The rationales for the High Court of Justice were consistent throughout the 1650s. Robert Jermy, a local Norfolk officer, for example, wrote to William Lenthall, the speaker of the House of Commons, in December 1650 during the winter rising and pleaded for a tribunal that would inspire terror: “it will be no end to try them by jury, but either to make some exemplary by a martial trial, or by the High Court of Justice.”Footnote ¹³⁹ It was also safer. The spymaster Thurloe was delighted in 1656 that parliament had authorized a new High Court of Justice. He stated to the diplomat John Pell that it was “thought more safe to try them in this way than by ordinary juries.”Footnote ¹⁴⁰ Cromwell shared these views. According to Bulstrode Whitelocke, when he begged the Protector not to try Slingsby and the rest by High Courts of Justice in 1658, Cromwell was “too much in love with the new way and thought it would be the more effectual and would the more terrify the offenders.”Footnote ¹⁴¹ These rationales were standard for justifying martial law.

However, neither the state nor the officers of the High Court of Justice sought to avoid the examination of evidence. The High Court of Justice provided defendants with an opportunity to defend themselves. It often allowed defendants to challenge the charge, obtain counsel, and always sought to examine often weighty evidence. One of the longer cases heard before the High Court of Justice was that of Christopher Love in 1651, a London Presbyterian, who was accused according to an article listed in the 1650 act establishing the High Court of Justice of holding correspondence with the Scots for the advancement of the cause of Charles Stuart. It allowed Love to bring in Matthew Hale, a young and promising jurist, who vigorously challenged the validity of the charge based upon what he thought was faulty wording and lack of proof. And this was after Love had already claimed exceptions to the charges laid before him. However, Hale's and Love's arguments were not effective, in no small measure because they had no jury to convince.Footnote ¹⁴²

From other accounts that we have of the workings of the court, the commissioners judged facts soberly. The best evidence we have of the internal workings of the court comes from 1654, during the trials of the attempted assassins of Cromwell, Fox, Gerard, and Vowell, because a written account by its president, John Lord Lisle, has survived.Footnote ¹⁴³ After the establishment of the court, the named commissioners met at Middle Temple. Sir Thomas Widdrington, a commissioner of the Great Seal, came to administer the oath to each commissioner, which forced them to act truly. Several had reservations about taking it. Justice Atkins of Common Pleas, for example, begged for more time to make his decision before he took the oath. Two days later, he informed Lisle that “he had already taken several oaths as a serjeant and as a judge to do nothing contrary to the laws of England.”Footnote ¹⁴⁴ In spite of this rejection, Lisle managed to obtain enough men to take the oath to meet the quorum of thirteen mandated by the ordinance. The trial opened in Westminster Hall, which according to Lisle was “very full of people.”Footnote ¹⁴⁵ Like the courts martial of the 1640s, the High Courts of Justice were open to the public. Fox came first and declared he would confess to his deposition. The other two eventually pleaded not guilty. The court heard several eyewitnesses who testified viva voce to the suspect's guilt. It then adjourned to the Painted Chamber to deliberate. After reviewing the evidence, Lisle posed two questions to each of the justices: whether the suspect was guilty of plotting to raise forces against the protector, and whether the suspect was guilty of compassing the death of the protector. In both cases, the commissioners voted in the affirmative for Fox and Gerard. For Vowell, they only voted on the first question, also finding him guilty. This voting system was consistent with that of a court martial. The three conspirators went to their deaths shortly thereafter.

If there was not enough evidence, the High Court acquitted defendants. This happened to John Mordaunt, a royalist plotter, who was arrested and charged with traitorous conspiracy in the spring of 1658. On 25 May, another charged with treason, Sir Henry Slingsby, was tried before the court, which adjourned until 1 June. In between, one of the chief eyewitnesses against Mordaunt named Mallory, who could prove he engaged in traitorous correspondence with Charles Stuart, escaped from prison “with the assistance of a Maid which served Mr Mordaunt he took a Disguise and a Purse she brought him.”Footnote ¹⁴⁶ Without its key witness, the High Court of Justice brought Mordaunt before it.

Mordaunt began the trial by engaging in a strategy that mirrored those of many who came before the High Court of Justice. Before he plead, he attempted to argue that he deserved counsel and that he should be tried before a jury. The Petition of Right and Magna Charta, according to Mordaunt, afforded him this right as an Englishman. The court responded that he did not need a counsel for matters of fact, and that the Act by which it sat did not require that the defendant be read the charges against him before he plead. After a fairly extended back and forth—this was not uncommon—Mordaunt finally plead not guilty to the charge of treason. Specifically, Mordaunt was charged with conspiring to levy war and alter the government of England, promoting Charles Stuart to be king of England, and communicating with Charles Stuart and his adherents in order to achieve this aim.

The attorney general then called two witnesses to advance the state's case, John Stapely and Anthony Stapely. But the witnesses were problematic. John Stapely only testified that he heard Mordaunt say that Charles had written to him, but not that he had received commissions from Charles. Further, he could not swear upon oath that he heard Mordaunt say that Charles had wrote to him, only that he thought that was what Mordaunt had said. The second witness, Anthony Stapely, who testified that Mordaunt, in a conversation in the Half-Moon Tavern, told him to be in readiness for a rising, and that he had four commissions. Stapely could not remember all the exact details about the plan. And the only other witness to the conversations at the Half-Moon tavern was Mallory, who had escaped from prison before he had to testify against Mordaunt.Footnote ¹⁴⁷ Several officers came before the court to swear what information Mallory was going to provide and how he escaped, but they could not replace his testimony.

Mordaunt jumped on the weaknesses of the prosecution's case. No one saw the commissions, and neither witness could confirm the other's story. All of the evidence, according to Mordaunt, “can amount to no more than one single Testimony.”Footnote ¹⁴⁸ The court was split: nineteen thought that Mordaunt was guilty, but nineteen others wanted to acquit him. Some probably had been bribed by Mordaunt's wife into moving for his acquittal.Footnote ¹⁴⁹ However, others were persuaded that not enough evidence had been shown to prove his guilt. The lord president, ultimately, sided with Mordaunt. He was skeptical of Mordaunt's innocence: “I will not say you are Guilty, but ask your own conscience whether you are or no.”Footnote ¹⁵⁰ There was not enough evidence for conviction. Mordaunt was acquitted.

Mordaunt's case was unusual. But the ways in which the court examined the evidence against John Mordaunt was not unusual. In the other cases, the prosecution simply had much more evidence. The power invested in the High Court of Justice was not limitless or arbitrary. It followed its own rules.

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We know that the High Courts of Justices of the 1650s were adapted courts martial because they were consistent in procedure and in substantive law with courts martial. They were summary jurisdictions. They were tribunals that had no distinction between judge and jury. None of these tribunals required an indictment proven by a grand jury. These tribunals had jurisdiction over treasonable offences related to war. The makers of the High Court of Justice incorporated these ideas from martial law. Initially, they even wanted to call the court a “court martial.” They changed the tribunal's name but not its nature. They authorized martial law to control discretion.

The High Courts of Justice were martial law jurisdictions that operated at Westminster, often in peacetime. The enemy was not within twelve miles of London with its banner raised. Nor were the Courts of Westminster closed. The name change was thus almost certainly an attempt to disguise the authorization of a martial law jurisdiction. MPs were embarrassed but not deterred. They knew about the Petition of Right and its restraints, even if they recognized that martial law jurisdiction was useful and perhaps in their mind necessary in prosecuting those who through their actions, not through their birth, had declared themselves to be enemies of the regime. The name change fooled few. Critics of the regime, and just about every defendant who came before the High Court, cited the Petition of Right and Magna Charta as reasons why they should be tried by their peers.Footnote ¹⁵¹ But perhaps they were asking too much of the Petition of Right. After all, its makers had never anticipated parliamentary control over the armed forces or the governments of the 1650s.

In authorizing martial law, parliament did not seek to authorize arbitrary power or extralegal authority. It was not authorizing unfettered military rule. Indeed, martial law was enticing for the exact opposite reason. Under intense pressure, MPs, those prosecuting the war, and state officers used the norms of martial law—its established substantive law and procedure—to bring order to what was increasingly a zone of legal chaos and to ensure that discretion would remain in the hands of those loyal to the state. It enabled the prosecution of some of the most controversial and perplexing cases of the period, which often involved plots and conspiracies, and it helped advance new treason laws for the new regimes. It was the law in martial law that was so useful. In their application of martial law, MPs were relying on a tool that predecessor regimes had also relied upon: for martial law had already been an important component of the early modern English legal system, hidden in plain sight.