In an undertaking on a daunting scale, Eunan O'Halpin and Daithi Ó Corráin have set out to establish how many people died ‘as a result of Irish political violence’ between April 1916 and December 1921, to identify their background and record who was responsible for killing them. So far, the total has reached 2,850. Even this apparently straightforward programme raises one or two difficult questions. How, for instance, to determine the political nature of each death? The inclusion of cases like Bernard Doherty, shot ‘most likely by a loyalist’ in Derry during a lull in rioting in May 1920, or Sarah Medalie, who had a heart attack during a military raid in Cork city in December that year, may stretch the notion held by many of revolutionary turmoil, as indeed may the forty-five suicides listed here. Accidental deaths, like Private Clarkson of the Royal Lancaster Regiment, shot on sentry duty outside the Chief Secretary's Lodge in Phoenix Park, by another guard who was changing the magazine of his rifle, were far more common than perhaps anyone has realised. Indeed, nearly half of all conflict-related military deaths between 1919 and 1921 were by misadventure, many by mishandling of weapons — certainly in part a symptom of the fact that the post-war British army consisted overwhelmingly not of war veterans (who were the first to be demobilised) but raw recruits. A different kind of accident seems to have killed Sarah Fitzpatrick, a showgirl shot in a tussle with her ex-boyfriend, an Auxiliary police inspector, in February 1921.

It is important to note, as the editors do, that fatalities alone hardly provide a precise ‘index of the level of political turmoil or its impact on people’. But deaths are, of course, uniquely significant, and recording them forms not just an index of violence but also a commemoration. Establishing the background — regional and religious — of the dead is a reasonably straightforward matter, but determining occupational status can be more problematic, not least because many people had multiple occupations. The nature of fatal casualties shifted markedly after 1916, when the proportion of civilians, and particularly women, was much higher (the rate of female deaths fell by nearly two-thirds after 1916) and there were no ‘sectarian’ or targeted killings. The pattern of deaths only indirectly reflects the level of disturbance. The absence of fatalities in the first eighteen days of 1920 is striking, for instance, especially as ten people had died in the previous eighteen, and the I.R.A. launched a series of assaults on police stations early in the year. Conversely, the death of thirty-five people in November 1921, four months into the supposed peace which followed the Truce, may seem at variance with the general state of the country.

Another, perhaps less difficult but still crucial, question may be whether the revolutionary violence can be said to have ended before the Civil War began. Presumably, the arbitrary terminal date of 31 December 1921 (meaning that those who died of injuries suffered before it were not included) was chosen partly to make the whole project more manageable. In fact, the number of deaths in December — twenty — is enough to indicate that the conflict was far from over. But establishing precise statistics of deaths in the civil war remains almost as challenging as it was when Michael Hopkinson noted, over twenty years ago, that there are no means of reaching ‘even approximate figures’.

In scale and intent this work compares with Lost lives, the epochal compilation on the Northern Ireland conflict by David McKittrick and his fellow editors, but it has the advantage of being able to go further beyond press reports in search of source material. Simple journalistic methods obviously cannot be applied a century on, but sources like the Bureau of Military History witness statements, only available since the early 2000s, and many official papers as well as secondary research works, have been mined to good effect here; so also are the Military Service Pensions records, though these were still emerging slowly from their long imprisonment. The endnotes show impressive persistence in pursuit of detailed verification. As Professor O'Halpin makes clear — in the light of an adjustment of his own family's received memory — the results may be uncomfortable for some: ‘In seeking the truth, be careful what you wish for’; new evidence may qualify or contradict family or communal narratives, and some readers may be offended by the resulting accounts. This is, as it were, everyday revisionism.

This book forms at the very least an impressive compilation, but it is also somewhat more than this. On the face of it, a dauntingly long catalogue is a rather forbidding proposition for any reader, and it is unlikely that many (reviewers perhaps excepted) will take it all in. Many may do no more than look up relatives or names they are familiar with. A number of the entries are indeed necessarily sketchy, bare bones. Yet, the nature of the more substantial essays, and their pungent fluency, is such that the book can be read through continuously, forming a multifaceted quasi-narrative. Cumulatively, the compilation creates a remarkable sense of the historical experience of insurgency and revolution. Piecing together an overall narrative of the conflict may be an expectation too far. What certainly can be found are explanatory threads of numerous key elements, most obviously the lived experience of armed conflict (Sarah Medalie's heart attack is a sad instance), the nature of the insurgent forces and their relationship with the people, and the operations of the security forces. Small sagas like the death of three Auxiliary police in an ambush at Clonfin mounted by Sean MacEoin's north Longford flying column on 2 February 1921 abound, with their telling details – MacEoin apparently congratulating the survivors who had fought until they ran out of ammunition, before disarming and releasing them.

The focus frequently opens out to set events in wider context, or extends to provide a follow-up. The substantial essay on the Croke Park killings on 21 November 1920 is a good example, as is that on the Kilmichael ambush. So is the inclusion of the deaths in India resulting from the Connaught Rangers’ mutiny. The essay on Mary Lindsay, probably the most famous Protestant ‘informer’, killed after perhaps a month's imprisonment by the Cork I.R.A. in February and March 1921 (the exact date of her death is uncertain, and her family remained unaware of her fate until a few days before the Truce – the Cork No.1 brigadier later expressed surprise that the Ministry for Defence had not been notified) is a fine instance of calibrated humanity. We get plenty of pithy judgments — for instance on Thomas MacDonagh, ‘an ineffective commander almost unhinged by emotional strain’ — and careful assessments of likely motivation for killings in situations which were often murky to say the least.

The entries, whether brief or extended, are generally models of clarity. Inevitably, some of the terminology used will not necessarily be known to all readers – noting that John Stokes, killed at Rearcross in Tipperary on 12 July 1920, was ‘the first defence of barracks sergeant killed by the IRA’ is not self-explanatory. Some remarks are perhaps not strictly necessary in a work of reference, such as the information that Lloyd George ‘gleefully instanced this case’ (that of Ellen Morris, killed in a bungled I.R.A. raid in Wexford in February 1920) to make a political point. And it may be questioned whether killings in the midst of intense fighting, even if unjustified, are rightly labelled ‘cold-blooded’. But such judgments give the text real character.

Why were people killed? The issue of targeting can be a sensitive one, and two categories will always remain contentious — those killed ‘while attempting to escape’ and those ‘executed’ as spies or informers. The number of the former listed here — fifty-four — with nearly three times as many more shot because they ‘failed to halt when called upon’ — may indicate that crown forces operated, as O'Halpin says, ‘with extraordinarily lax rules of engagement’ and had in effect a licence to fire without warning which was highly unusual in ‘peacetime’. No such rules of engagement apply to an insurgent movement, of course, and though the I.R.A. always claimed to be rigorous in its investigation of alleged informers, there were many mistakes — as when James Dalton, an intelligence officer in the Limerick I.R.A., after being cleared by a court martial of a charge of meeting British detectives, was gunned down outside a pub. Surprisingly, for those who might assume that the I.R.A.'s primary objective was to contest the governance of the country, it hardly ever targeted the higher judiciary or lower officers of the legal system. One of the few, Thomas Walker, a process-server in Sligo, who was abducted by the I.R.A. and dumped in a quarry, was it seems killed as a spy rather than a civil bills officer.

Though the editors suggest that sectarianism can seldom be clearly assigned as a motive, many killings were certainly experienced as sectarian by the victims’ communities. A striking proportion of all deaths happened during riots, most of which of course took place in northern towns and for sectarian reasons, though it usually remains impossible to determine if particular victims were deliberately targeted on sectarian grounds. The deadliness of riots, frequently provoked by the killing of policemen, seems disproportionate to the very small number of police killed by the I.R.A. in Belfast in 1920 and 1921. This may, as O'Halpin suggests, ‘raise questions’ about the planning and leadership of anti-nationalist action, though he does not go on to spell these out.

A fair number of fatalities are not listed here. On the most contentious of all issues, the ‘disappearances’ of the revolution, this work suggests that in the cases of over 100 I.R.A. killings (of civilians, as well as police and British troops) the ‘naming’ of the dead — the term used by Drew Gilpin for the reporting of American Civil War fatalities and identification of their remains — is still impossible. Fifty-six were in County Cork (substantially fewer than was suggested to Ernie O'Malley in 1939 by a senior Cork I.R.A. officer). In these cases, ‘long-term concealment was attempted’. Not all such concealment can be assumed to have had malign motives; operational necessities — bearing much more heavily on the insurgents than on Crown forces, which seldom bothered to conceal illicit killings — may have driven many. Eighteen per cent of soldiers — over seventy men — were killed by the I.R.A. after they had surrendered, or while off-duty and unarmed. In addition, a probably unknowable number of deserters who did not, as the army assumed, succeed in escaping, fell into the hands of the I.R.A. and were killed

In some cases, recent publicity — for instance the investigation of Peter O'Carroll's death on the B.B.C.'s ‘Who Do You Think You Are?’, which proposed a theory about the killers — might be worth mentioning. It seems odd not to mention that Kevin Barry, executed on 1 November 1920, became the subject of one of the most resonant republican ballads, one which is of more than recreational importance since it has ensured that the charge of torture against his captors remains current.

An extra dimension has been added by including the compensation payments granted by both British and Irish authorities, which offer an interesting commentary on the perceived value of life — a fundamental social question which is seldom if ever openly debated. Some Auxiliary police widows received over £5,000 — as did the widow of former R.A.F. pilot Cecil Guthrie, who survived the Kilmichael ambush only to be seized by the I.R.A. next day when he tried to commandeer a vehicle near Macroom, and possibly beaten to death for his earlier behaviour. (Tom Barry in his role as liaison officer during the Truce later gave misleading information to the British about his death). Relatives of other Auxiliaries killed in the ambush received only £1,000, though elsewhere payments of between £2,000 and £3,000 (as for Thomas Walker's widow) appear to have been common. A few, such as the figure for General Hanway Robert Cumming's widow — £10,000 — were dramatically more substantial.

This project has created a key resource for understanding the revolutionary period and an important centenary marker. If there are some who, as the authors no doubt anticipate, will dispute their version of events in particular cases, that conversation should help to keep this work a living monument.