Biographies have a provenance that all too often is not vouchsafed to the reader. The biographers’ acknowledgments, for example, usually tell only half the story, suggesting that research is just a matter of accessing archives and conducting interviews. The “Story,” however, relies as much on a master narrative established by the biographical subject and his acolytes. And in certain cases, as with Michael Collins, the biographers – there have been 12 of them – in effect become apostles.

In “Mick: The Real Michael Collins” (Viking, 480 pages, $27.95), Peter Hart establishes a baseline text anchored in primary sources that previous biographers have neglected, such as public records and newspaper accounts. Because so much apocryhpha has arisen around Collins, whose career ascended with the 1916 Easter Rising and then flourished with the founding of the IRA, the legend of the man who finagled Ireland’s fate as an independent government has practically replaced his biography. Mr. Hart’s interest, then, is not so much in evading data to deliberately undermine the Michael Collins myth as portraying the “real” person.

Mr. Hart’s assurance that he does not intend to debunk his subject, however, cannot gainsay the fact that the “real” man had trouble passing exams for post office jobs in London and was never very proficient at mathematics, and yet he became the banker for the Irish Revolutions – the keeper of the books, so to speak, with an organizing capacity and energy that surpassed all his rivals for power. But if your image of Michael Collins is that of Liam Nee son in Neil Jordan’s 1996 film, then Mr. Hart’s portrayal might well seem debunking. “That his destiny was in his blood has … become a staple of the Story,” Mr. Hart observes and goes on to suggest that Collins’s background was hardly different from those of a generation of young men who shaped the fate of modern Ireland. In a similar vein, he writes that “biographers have created an image of Collins as the genius of the resistance, the man in charge.” In fact, Collins showed little sign of political charisma before a power vacuum developed when Eamon DeValera turned against the negotiated treaty with Britain that created an Irish Free State.

Studded through Mr. Hart’s biography are slighting phrases such as “the standard version” and “biographical convention.” Such skepticism about the canon of Collins biography serves not only to enhance the singularity of Mr. Hart’s biography. He has steeped himself so deeply in previous biographies that he has the authority to assert his independence. Mr. Hart is no Gradgrind of fact; he reports the legend, the theories about Collins’s behavior, and evokes the aura of the conspirator, negotiator, politician, and terrorist. And he is not smug about his impressive achievement: “[W]hat we know is dwarfed by what we do not and never will.” Such statements make this a book about the nature of biography itself.

Collins believed in the efficacy of political violence, and Mr. Hart endorses his subject’s view that Britain agreed to the establishment of a free state because the Irish proved they would continue to fight for it. But the violence also turned against the 32-year-old Collins when he was shot and killed in an IRA ambush.

Mr. Hart’s description of that death scene is crucial to his work. He rejects the idea that Collins’s murder was anything more than an IRA operation. Collins, in other words, was not specifically targeted, and his death, in that sense, was “banal” – one of too many that occurred amid the chaos of establishing an independent Ireland.

In his conclusion, Mr. Hart provides a remarkable tribute to Collins:

Michael Collins was a creature of opportunity and an astute and lucky political strategist, but there was still more to him than that. Opportunities are necessary, but they have to be made – or, when they appear, exploited to maximum advantage. And strategies have to be correctly implemented to be successful. The timing has to be right; allies have to be in place; friends have to help; opponents have to be circumvented, turned, or beaten; rules have to be changed, broken, or upheld; crises have to be engineered or defused – all the friction of political warfare has to be overcome. All this requires hard work, organizational ability, tactical skill, personal persuasiveness.This is the stuff of political mastery, and Collins possessed it all.

Collins was a great networker, Mr. Hart adds, with a knack for making people feel special, but he never clouded his judgment with sentimentality, and he was a genius at waiting until the last possible moment to make a decision, thus keeping “all possible options open.” But this paragon of politics “hadn’t always had these skills, and it is obvious from the ever-lengthening list of his enemies that he didn’t always exercise them,” Mr. Hart points out. Indeed, the biographer shows that Collins could be a short-tempered micromanager who alienated many trustworthy and able associates.

As a historian, Mr. Hart feels compelled to measure his man against the greatest heroes – insurgent leaders like Martin Luther King Jr. and Nelson Mandela and establishment statesman like Winston Churchill and Franklin Roosevelt. Collins does not quite belong in this august assemblage, Mr. Hart concludes. Yet it seems to me that the biographer’s final words grant his subject, and the biography itself, an indispensable claim on our conscience:

But, in the time allotted to him, he became the most ruthless, the most calculating and the most powerful politician in modern Irish history, and his triple legacy of independence, partition and the IRA have challenged his legatees ever since.