From prisoner to peace maker - he made unthinkable now acceptable
He did the unthinkable and made it acceptable - from toasting Queen Elizabeth to attending Armistice Day events for the World War I dead. When Martin McGuinness became convinced that armed resistance should be set aside in favour of negotiation and ultimately power-sharing, he carried his community with him. That's why his legacy is peace.
Only the ungracious would begrudge him the hard-earned title of statesman. While he began in violence, he ended in reconciliation. An overview of his career shows someone whose evolution in thinking helped to shape Irish history and reconfigure it for the better.
Once he signed up to a settlement, he was sincere about building bridges with unionists, laying the foundations for peace after three decades of violence.
Observers who saw him only on news bulletins weren't necessarily aware of the charm and humour which characterised him, how courteous his demeanour. He was at once a simple, modest man and a complicated, ambitious one - not for himself personally but his goals.
His life story represents an extraordinary journey, leaving school at 15 and winding up as deputy first minister in Stormont - forging a friendship en route with DUP founder Ian Paisley, his diametrically opposed political opponent.
How was that possible? Perhaps the clue lies in his hobby. In rare opportunities for down time he was a fly fisherman, a pastime known as "the contemplative man's recreation" for those who are thinkers, and have patience.
Nobody, least of all himself, could have predicted the permutations of his life story. He transitioned from republican prisoner, with sentence passed on him by the Special Criminal Court in Dublin, to IRA chief negotiator during the peace process which foreshadowed the Good Friday Agreement, to donning white tie and tails for a royal banquet in Windsor Castle.
Once, he was banned from entering Britain under prevention of terrorism legislation. Yet he rose to his feet as 'God Save The Queen' was played at that state dinner in 2014, held in honour of President Michael D Higgins's historic visit, and raised a glass to Elizabeth II's health. Not every republican was with him in spirit, but he believed it was right to do so.
Violence rather than political solutions featured at an earlier stage of Mr McGuinness's life story, as an IRA chief commander in Derry. And to some, he will always have blood on his hands.
Outside that Windsor Castle event, a knot of protesters gathered. The sister of a woman killed in the 1974 Birmingham pub bombings said he should be arrested, not feted. The father of a 12-year-old boy killed in the 1998 Omagh bomb called him a terrorist and insisted the public should be reminded of his past.
Mr McGuinness was sentenced to six months in jail after being found near a car containing explosives and ammunition in 1973. Later, he claimed to have left the IRA in 1974. This wasn't particularly credible, and there were persistent reports he was on the IRA army council.
But most people recognise that in later years, he worked with energy and commitment to construct a peaceful future for a conflict-torn society. That required courageous leadership, steadfastness under opposition and a persuasive bent.
He chose his words carefully, and could speak with grace. Consider his rationale for shaking Queen Elizabeth's hand - a decision which not everyone in the republican fold was easy about. His account shines a light on his ability to consider other people's perspective, and explains his skill as a negotiator.
"I have many reasons why I shouldn't meet with Queen Elizabeth, but she too has many reasons why she shouldn't meet with me - but we both thought it was an important thing to do," he told the BBC's Jeremy Paxman, who asked why he was breaking bread with an "occupying power".
One of the most unlikely chapters in Mr McGuinness's story was his friendship with Mr Paisley. It was an extraordinary reversal of his position in the 1970s and 1980s. But the Derryman was no bigot - he simply wanted to bring about change in the North. It was the system, not people, he loathed; he was closer to the inclusive United Irishmen tradition of Protestant, Catholic and dissenter.
Reflect on Mr McGuinness's response to the death of Mr Paisley, with whom he worked closely in Stormont between 2007 and 2008: "He was a very strong supporter of the peace process and once he came into the office of the first and deputy first minister, when we made the agreements that we made, he threw himself heart and soul into it. Our relationship confounded everybody."
His tribute to DUP founder Mr Paisley, or Baron Bannside as he became, could just as readily be applied to himself. Mr McGuinness was serious about reconciliation and conflict resolution. Parity of esteem was a two-way street with him.
If he had been insincere, the Paisleys would have spotted it. Instead, Ian Paisley Junior said "thank you" publicly for helping to end the cycle of violence to Mr McGuinness, on his retirement in January. That endorsement from Mr Paisley, one of the DUP's group of eight Westminster MPs, also showed leadership and a desire for reconciliation, incidentally.
He suffered a setback in 2011 during the presidential election, when he came third behind Mr Higgins and Sean Gallagher. It was a particularly testy campaign: he was challenged about his IRA membership, and relatives of those killed during the Troubles objected to his running. People in the Republic struggled with the idea of anyone with a background in violence holding high office, although those in the North were obliged to make an accommodation with it. The campaign emphasised how partition has taken root in the minds of the current generation south of the Border. His 13.7pc first preference votes must have been a disappointment.
And so it was back to Stormont, where his relationship with Peter Robinson was decidedly more businesslike than with Mr Paisley. With Arlene Foster, however, it all fell apart. Words failed there.
Yet he continued to believe in their power. "Dialogue is the only option," he stressed in his resignation statement. After all, it changed an Orange state radically.
Mr McGuinness transitioned, and moved others with him. It's likely some people died because of him - but incontestable that more people are alive today because of him and others, on both sides.
Ian Paisley Junior was right to express gratitude in public. As someone who grew up in the North during the Troubles, I take my lead from him and repeat it. Thank you, Martin McGuinness.