The 1642 Adventurers’ Act aimed to raise a loan of £1,000,000 to fund an army controlled by the English parliament that would suppress the Irish rebellion that began on 23 October 1641. Those who loaned money would be repaid with Irish lands. It is well known that the adventurers who invested in the act played a key role in the controversial land settlements of the seventeenth century. What is less known, however, is how some of the leading figures who managed the adventurers’ investment exerted considerable political influence throughout the crises of the mid-seventeenth century and how they viewed their speculation in Ireland as part of a much broader mercantile venture that spanned the growing global economy. Empire and enterprise provides us with a detailed and nuanced picture of these developments.

1,300 people invested in the act but their interests were represented by twenty or so figureheads, most notably Maurice Thomson, a merchant from a relatively humble Hertfordshire background. Thomson, like other adventurers, made his fortune in Virginia. During the 1620s and the 1630s, Thomson and his cronies managed to accrue significant wealth by securing much needed labour (i.e. indentured servants) in return for land. This occurred largely because Charles I spent the 1630s focusing on the redistribution of internal monopolies in England and Ireland. In 1640, Charles turned his attention to the burgeoning Atlantic world trade network which alarmed Thomson.

The outbreak of the first bishops’ wars in Scotland and the Irish rebellion presented London merchants with the opportunity to augment their political influence in the face of Charles's meddling. The primary motivation for this, Brown argues, was not the desire for political office but profit. Thomson could influence many of the key figures within the English parliament, most notably John Pym, because they too had considerable financial interests in the mercantile Atlantic world. Such connections allowed these merchants to push for the passage of the Adventurers’ Act. Although the monies were supposed to fund an army to suppress the Irish rebellion, instead they were diverted to pay for an English parliamentary army. Eventually, the adventurers would control not just the financing of the English parliamentary army but the entire parliamentary war effort itself. Here, Brown broadens our understanding of the factors that led to the outbreak of the first English Civil War.

In order to secure a return on the adventurers’ investment the Irish confederate war effort had to be totally defeated. This shaped the adventurers’ political strategy and dictated which particular faction they supported at different times. For example, despite providing significant funding for the covenanting army in Scotland, growing suspicions among the adventurers of Presbyterian influence in English politics meant that they began to support the New Model Army. Mindful of their investments in the east, furthermore, the adventurers also sought to protect their international trade routes which were becoming more profitable due to the increasing use of slaves. In the late 1640s, Dutch sailors offered their protection to the Irish confederate navy which threatened the adventurers’ commercial interests to the east and in the Atlantic world. This, Brown argues, provided an impetus to fund Oliver Cromwell's invasion force of Ireland. Afterward, Cromwell prioritised claims of army officers to Irish lands, which aggrieved the adventurers. Thus, to curb the adventurers’ political influence Brown suggests that Cromwell dismissed the rump parliament, a new and thought-provoking argument. By 1659, it was clear to Thomson that the only way the adventurers could secure their return on Irish lands was to support the restoration of Charles II. The adventurers’ pivotal role in this is evidenced by Charles II's decision to exclude the vast majority of Irish Catholic landowners from the terms of the Act of Oblivion.

Empire and enterprise sheds light on the role of the financial and mercantile world in shaping English politics and in providing and managing the English parliament's revenues in the 1640s. Brown's work is ground-breaking in that it locates the adventurers in their broader political and transatlantic trade context and illustrates how they viewed their investment within the increasingly globalised economy. It changes our understanding of how the English parliament was able to finance and man an army and navy so quickly, and it clearly illustrates how the adventurers’ influence permeated most of the major English parliamentary committees of the 1640s. Thus, it offers an important context to understand the confederate wars of the 1640s and the wider Wars of the Three Kingdoms. Finally, it reminds us that contemporary speculators saw Ireland as a laboratory for empire and a venue for economic exploitation.