The Michael Collins film threw the spotlight on Collins' irrepressible sparring partner and rival for the hand of Kitty Kiernan, Harry Boland. He is already the subject of a popular biography with a clear storyline by Jim Maher published a couple of years ago. David Fitzpatrick, a well-known specialist in the War of Independence period, has followed up with a full-scale and comprehensive biography supported by even more extensive quotations from primary sources.

Harry Boland came from a Fenian family. He played football for Dublin in an all-Ireland final in 1909. He joined the IRB and effectively inducted Michael Collins. Participation in the 1916 Rising and subsequent imprisonment gave him full membership of the revolutionary elite (as well as making him attractive to the girls). He played a vital role in 1918 in smoothing relations with Labour, who crucially gave Sinn Féin a clear electoral run.

His most important mission was his three years in America, spent lobbying for recognition, financial support and weapons. As rarely before or since, Irish and American politics became entangled, over membership of the League of Nations and the scope of future neutrality. His self-confidence six months on can be judged by his claim in a letter home: "We have put Bunker Hill back on the American map, and we have become the rallying ground of all good lovers of liberty." Nevertheless, it was an untidy and messy period, with gargantuan quarrels and jealousies between de Valera and the Irish-American leaders John Devoy and Judge Cohalan. Boland eventually had to expel Clann na Gael from the Irish Republican Brotherhood, with an insouciant ruthlessness.

For all that, the influence of America was a decisive factor in persuading the British government to negotiate. Lloyd George needed the US Congress to take a sympathetic view of heavy British war loans, something less likely to be forthcoming while Black and Tan-tyle repression continued in Ireland. On a brief visit home in the summer of 1921, Harry Boland was sent up to Scotland with a letter to Lloyd George on holiday but did not handle him entirely to de Valera's satisfaction. He was sent back to America rather than go with the delegation to London. Both he and Irish-American leaders John Devoy and Judge Cohalan were initially wrong-footed by the Treaty. The last two were determined to be on the opposite side to de Valera, with whom they had quarrelled, and on the assumption that he supported the Treaty denounced him for selling the pass, swapping positions with some embarrassment a few weeks later.

Kitty Kiernan's courting with both Collins and Boland is well documented, and she was not above playing one off against the other, if she felt she was not getting enough attention. Collins was, of course, the bigger prize.

The tragedy is that, as the two friends fell out both politically and romantically, neither were to marry and both were to die in the early stages of a civil war that would leave many of the most talented participants in the struggle for independence dead, and a newly independent country deprived of their vital further contribution.

Harry Boland was lively and engaging with real diplomatic skills, but he was not always serious. He was a communicator, not a desk man, and more a spokesperson and diplomat than a policy-maker.

In general, his words are a lively echo of debates current at that time. His brother Gerry and his nephew Kevin were later to be Fianna Fáil cabinet ministers, the latter ending up in political isolation over the North.

Harry Boland's summation of the future of British-Irish relations was sound: "We must have independence first, and inter-dependence afterwards."

He did not give serious thought to the Northern problem and glibly assumed that Ulster could be freed in the same way as the rest of the island.

Harry Boland has now at last been well-served by biographers. It is an illumination of how a popular art-form like the Michael Collins film can create the public demand, which helps to justify, at least from a publisher's point of view, the telling of the story in more detail, and the type of in-depth research to be found in David Fitzpatrick's book.

Much of the credit for this, I suspect, belongs to Harry Boland, the nephew, a leading light in the accountancy profession in the second half of the 20th century, who made the family papers available and encouraged the authors.