The loyalist assassin Michael Stone tried to kill him twice, once at a republican funeral. Stone recalled: “I planned to shoot McGuinness and Adams, two head shots, as they passed the roll of honour. That was their cenotaph, and that’s where they were going to die.” But his view was obstructed. He attends mass regularly – he did so on the morning of Bloody Sunday – and lists his hobbies as fly-fishing and chess.

Another regular activity, this time involuntary, was his detention in police interrogation centres, where he was questioned for up to seven days at a time.In more recent times, he has been to rather less oppressive institutions of the state, such as 10 Downing Street. He was particularly enchanted by Chequers, describing it as “a fairly amazing place, absolutely beautiful, with a very relaxed atmosphere”.Many see him as one of Ireland’s most fascinating politicians and, close up, he does a great line in twinkling geniality. Even the Spectator editor and Tory MP, Boris Johnson, succumbed to his “great friendliness and charm”.Yet the shadow of death has often been close. As an icon of implacable militancy, his approval of the new tack calmed hardliners.Although he has since become ever more deeply involved in politics, first as MP for Mid-Ulster, later as a member of the Northern Ireland Assembly, no one thinks he is pursuing power for its own sake or for personal gain. He has always lived in a little house in the Bogside; fathering four children in what is, by all accounts, an extremely stable marriage. It also cost many lives: the IRA killing, on average, 60 people a year.When Sinn Fein unexpectedly became an effective political vehicle in the wake of the 1981 hunger strikes, most republicans welcomed the development. However, some worried that the new direction would undermine the “armed struggle”.

And when some volunteers felt that Adams was rather too political for their taste, McGuinness played a key role in providing reassurance. The two men have had the closest of relationships ever since. The IRA was reshaped and streamlined to fight a long war, a lengthy conflict of attrition designed to eventually get the British out.The IRA managed to survive all that the British could throw at them, but its campaign did not push Britain out. Some of those years he spent in jail, serving two sentences in the Irish Republic for IRA membership.

Then, in the late 1970s, he, Adams and other militant Northerners seized control of republicanism, denouncing the southern old guard as soft and out of touch. The republicans demanded a united Ireland; the British declined and the conflict continued McGuinness recalled much later: “It’s like a lifetime away. We were only children really.”It left him with the sense that any chance of real negotiation was years away. It is an indelible part of their past and they will never repudiate it.A formative experience for McGuinness came a few months after Bloody Sunday, when the Conservative government flew him, with Gerry Adams and other republican leaders, to London for secret talks. Although he and his republican movement have moved on since the turbulent times of hectic violence, when he routinely handled rifles and nail bombs, they still regard those times with pride. He was lucky to survive that period: many of his IRA associates did not.

Last week he told the tribunal during his two days on the witness stand: “There was a state of war between the IRA and British military forces. This was a war area.” The IRA was not the only killing agency: the Army shot 13 people dead on Bloody Sunday (a 14th died later).One man’s terrorism is another’s freedom struggle and McGuinness – and republicanism generally – has never deviated from the defiant stance that he was fighting against a hostile army of occupation. He has excelled at most of things he has turned his hand to since he walked away from his last conventional job: preparing pre-packed meats at Doherty’s in Londonderry in 1971. He became a full-time street-fighter, rising to be second-in-command of the city’s IRA and then taking over as OC (officer commanding) just after Bloody Sunday.He proved gifted at guerrilla warfare, fashioning the Derry IRA into an awesome killing unit.