MARTIN McGuinness was a former IRA commander who went on to shake hands with Queen Elizabeth and dine at her table.
In 1972 it would have seemed absurd that she would one day greet a man who helped lead the Provisional IRA in a bloody campaign against British rule in Northern Ireland.
The Bogside that Martin McGuinness grew up in was highly charged and he quickly became immersed in a political turbulence going on around him emerging as a key figure at the outbreak of the Troubles.
The future deputy first leader admitted to the Saville Inquiry into the Bloody Sunday shootings that he was second in command of the Derry IRA in the early 1970s.
Security agencies claim he served twice as chief of staff. While he told Saville he left the IRA in 1974, it has been claimed he served as chief of staff from 1978 until 1982. Security agencies believe he resumed the position in 2001.
Mr McGuinness was born in 1950 in the shadow of Derry’s Celtic Park GAA ground. His family was well known and respected in Derry. After leaving school at the age of 15 he found employment at Doherty’s Butcher’s in Derry.
Mary McAleese: The contribution of Martin McGuinness to politics in Northern Ireland was 'enormous' pic.twitter.com/MqaQNUTQSd
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However he emerged as a key political player when he appeared at a press conference at which then Secretary of State, William Whitelaw was given the IRA’s conditions for a ceasefire.
On the run in the early days he spent much time in nearby Inishowen. He was arrested in 1973. Refusing to recognise Dublin’s Supreme court, he was sentenced to six months on arms charges.
Mr McGuinness was Sinn Fein's chief negotiator of the 1998 Good Friday Agreement. He secured IRA arms decommissioning in 2005 and shared government with former enemies in Belfast as deputy first minister.
He became MP for Mid Ulster in 1997.
He was returned as a member of the Assembly for the same constituency following elections and went on to become minister for education. He scrapped the 11-plus exam, which he had failed as a schoolboy.
During his time as deputy first minister he forged such a good working relationship with former DUP leader and first minister Ian Paisley that they were dubbed "the Chuckle Brothers".
But it was his more strained relationships with Mr Paisley's successors, Peter Robinson and Arlene Foster, that led to difficulties in recent years at the top of the power-sharing executive.
Recently he has been plagued by ill-health. When he announced his resignation in Belfast earlier this month he appeared gaunt and tired.
As well as reaching out to unionism, the Sinn Féin leader would meet Queen Elizabeth and later to publicly toast the British monarch.
He has angered dissident republicans with his support of the PSNI and his unequivocal condemnation of their campaign.
In 2007, on a visit to the US with Ian Paisley, he even remarked about how once sworn enemies had come together: “Ian Paisley and I never had a conversation about anything – not even about the weather – and now we have worked very closely together…This shows we are set for a new course.”
However Mr McGuinness' dream of a united Ireland - he also unsuccessfully stood for Irish president in 2011 - was unfulfilled during his tenure and doubts remain among some republicans about what they have gained through entering Stormont.
But his period in office helped consolidate the peace and repair some of the many fissures in a once-bitterly divided Northern Ireland.