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LONDON — In life, former Irish Republican Army commander Martin McGuinness was a killer who turned peacemaker — one of the world’s most intriguing political figures.

In death, he was equally divisive. Victims of IRA violence condemned him but former adversaries showered him with praise for playing a key role in ending a struggle that claimed some 3,600 lives.

His death on Tuesday posed a question: Do you judge a man by what he was or what he becomes?

In the years covering the “The Troubles” in Northern Ireland, where I was born and raised, I knew some of McGuinness’ gunmen. I was friends with some of his campaign’s victims and others killed in retaliatory violence. I found him warm, straightforward and always an enigma.

A former teenage gunman, McGuinness risked assassination by negotiating with his enemies. The complexity of his life and legacy can be seen in the tributes paid to him.

Queen Elizabeth II's uncle was murdered during the IRA’s struggle to end British rule in Northern Ireland. But she appeared with him publicly and spoke to him privately. After his death, she personally wrote to his widow, Bernadette.

Former President Bill Clinton, who met McGuinness many times and worked with him on a peace settlement, hailed the former fighter during Thursday's funeral.

Former President Bill Clinton touches Martin McGuinness's coffin on Thursday. NIALL CARSON / AFP - Getty Images

"After all the breath he expended cursing the British, he worked with two prime ministers and shook hands with the queen," Clinton told the 1,500 people packed into Saint Columba's Church in Londonderry, known also as Derry. "He persevered and he prevailed, he risked the wrath of his comrades and rejection of his adversaries."

Former British Prime Ministers Tony Blair and John Major praised his work on the 1998 Good Friday Agreement that largely ended the conflict.

“We could never have done it without Martin’s leadership, courage and quiet insistence that the past should not define the future,” Blair said after the death was announced.

McGuinness' former partner in the Republican movement, Gerry Adams, said to cheering crowds: "Martin was not a terrorist. He was a freedom fighter."

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As well as targeting British troops, McGuinness' men and women detonated bombs that blew children to pieces, killed civilians who helped rebuild police stations, murdered men in front of their children, shot and killed women they accused of disclosing information about IRA activities.

So for many, the past is preeminent.

“UNFORGIVEN” ran the headline in The Sun newspaper — Britain’s most popular tabloid — after McGuinness died. “IRA killer can go to hell, say families.” On its cover, the Daily Mail splashed two photographs of wounded and bloodied civilians in the aftermath of IRA bombings.

(Coverage of McGuinness' death in both papers’ Irish editions was much rosier.)

Former government minister Norman Tebbit, who was injured and whose wife was paralyzed in the IRA’s attempted assassination of Prime Minister Margaret Thatcher in 1984, was also not ready to forget and forgive.

“The world is a cleaner place now,” he said. “He was a coward … I hope he’ll be parked in hell for the rest of eternity.”

The shattered top four floors of the Grand Hotel in Brighton, England, which was devastated by an IRA bomb on Oct. 12, 1984. While it missed its main target — Prime Minister Margaret Thatcher — the explosion killed five others. AP

Conversely, Jo Berry, the daughter of a British lawmaker who was killed in the same bombing, called McGuinness “an inspiring example of peace and reconciliation.”

In his statement, Irish President Michael Higgins chose to make no mention of McGuinness’ early life — an airbrushing of history untypical of the many other carefully nuanced statements.

History and morality are at the heart of the debate. As with another revolutionary leader, Nelson Mandela, do we judge McGuinness by the early violent acts he condoned and directed or by his later life as peacemaker and statesman?

“How a person’s journey started is of course important, but it is how it finishes which is actually more important,” according to Ian Paisley, Jr., whose father formed an unlikely friendship with McGuinness after years as a bitter enemy.

Northern Ireland's First Minister Ian Paisley and Deputy First Minister Martin McGuinness smile after being sworn in as ministers of the Northern Ireland Assembly on May 8, 2007. Paul Faith / AP

Rev. Ian Paisley, founder of the Democratic Unionist Party that advocated for Northern Ireland to remain part of Britain, was a firebrand protestant preacher. James Martin Pacelli McGuinness took his the unusual third name from Pope Pius XII.The two came together to share power in Northern Ireland after the Good Friday accords.

McGuinness never apologized for the many deaths — of policemen, civilians and British soldiers — that happened while he was an IRA fighter and commander. The furthest he got was “to acknowledge the hurt and the pain” violence caused.

Related: Anguish Haunts Northern Ireland's Retired Terrorists

His goal was to get the British out of Ireland and to achieve a united state, and his beginnings are key to understanding his legacy.

McGuinness’ journey started in Derry, where his fellow Catholics were the majority but Protestants ruled. As a young man he was turned down for a job as a mechanic because he was a Catholic, and instead became an apprentice to a butcher.

By the time British paratroopers opened fire on mostly Catholic demonstrators in the city in 1972, killing 14, McGuinness was an IRA commander. But two months later, he was being flown to London with other commanders for secret talks with the British government.

A British soldier drags a Catholic protester during the 'Bloody Sunday' killings on Jan. 30, 1972, when British paratroopers shot dead 13 civil rights marchers in Londonderry, which Republicans refer to as Derry. THOPSON / AFP/Getty Images

He took a dual path, in the media spotlight — even attracting the attentions of the Hollywood actress Jane Fonda — and as a secretive revolutionary who operated ruthlessly in the shadows.

Much of what happened in Northern Ireland over thirty years of low-level war is dark and morally tangled. The British state perverted democracy in order to preserve its rule by imposing courts without juries, internment without trial and banning free speech.

British forces colluded with Protestant killers in the murder of Catholics seen as a threat.

For decades, Americans donated to Noraid, which an American judge once called “an agent of the IRA, providing money and services for other than relief purposes.” Perhaps only after 9/11 were the full implications of funding such campaigns driven home to the Irish-Americans of New York, Boston and Chicago.

Martin McGuinness at a news conference in June of 1972 in Derry. Leif Skoogfors / Getty Images

The IRA murdered, yet more than one adversary spoke of McGuinness' courage in war and peace. Terrorists could detonate dozens of bombs in Belfast in a few hours, yet often telephoned warnings to clear people from the path of an explosion.

McGuinness was a non-drinking, churchgoing Irish revolutionary who supported English soccer team Manchester United and later became a fly-fishing grandfather and a passionate peacemaker.

Irish Times columnist Fintan O'Toole rounded up the man’s complexity when he wrote that McGuinness had been "a mass killer … whose personal amiability has been essential to the peace process.”

O’Toole concludes: “If he were not a ruthless and unrepentant exponent of violence, he would never have become such a key figure in bringing violence to an end."