He is the chief architect of the peace process, the man who for 30 years has led the opposition to the IRA within his own community while leading the constitutional nationalist case for a new dispensation in which his community shares and wields political power.
He is a truly heroic figure in Irish history. A serious and intense man, he suffered bouts of ill-health and depression over 30 years at the centre of the North's often intractable, bitter and hate-filled political process. He suffered enormous pressure and personal vilification as he paved the way for the entry of the republican movement into the political process in the early 1990s.
The ceasefires and the current - albeit incomplete and uncertain - peace process represent his vindication. Coming first to wide public attention as a Derry Civil Rights leader in the late 1960s, he moved beyond being seen simply as a nationalist leader. For over 20 years he was articulating a vision of a "new Ireland" achieved by persuasion, not violence.
In his new Ireland, the three unresolved relationships that he said were at the root of the Northern conflict would be resolved. These relations were those between the communities in the North, between the people North and South, and between Ireland and Britain. The resolution of these relationships should be reflected in new political institutions, he argued.
His constant repetition of this position led to its being dubbed "Humespeak". Some opponents and cynical commentators began to refer to Mr Hume's "single transferable speech". Mr Hume responded once to this reporter by saying: "The fact that you have to say something again and again before people listen to you doesn't mean you are wrong."
During dark periods in Northern Ireland his moral authority ensured the cause of northern nationalists retained a legitimacy when many in the Republic, Britain and abroad were repelled from that cause in the face of IRA violence.
BORN in January 1937 as the eldest of a family of seven, he grew up in an atmosphere of disillusionment and unemployment. His father, a Derry shipyard worker, was unemployed for 20 years.
He studied briefly for the priesthood at Maynooth and later completed a BA in French and modern history. He worked as a teacher in Derry, then in Strabane, before returning to his old school of St Columb's College in Derry. In 1960 he married fellow schoolteacher Ms Pat Hone.
Research for an MA thesis on the economic and social history of Derry prompted him to work to develop constructive self-help projects in his native city. In 1961 he founded the Derry Credit Union, something he still lists as among his proudest achievements. He later became national president of the credit union movement.
He has a passionate attachment to his native city, not just its Catholic community. He helped to found the Derry Housing Association, a private organisation which built new houses and renovated old ones. He wrote pamphlets and scripted and directed several films extolling Derry's industrial and tourist potential. In 1967 he gave up teaching to open a salmon-smoking industry with a partner.
The blatant gerrymandering, housing and job discrimination drew him inexorably to civil rights causes. He became seen as one of those best able to express the aspirations and frustrations of his city's Catholic nationalist community. He was in the leadership of the university for Derry campaign. The university ultimately went to Coleraine - a decision seen as blatant discrimination against the heavily Catholic region west of the Bann.
He became a committee member and then vice chairman of the Citizens' Action Committee and a key planner of the civil rights marches that ultimately led to the explosion of the North's unresolved conflict.
He was a strong advocate of non-violence and was uneasy with elements in the Civil Rights movement who did not share his outlook. When violent nationalism emerged from the Civil Rights movement in the late 1960s in the form of a resurgent IRA, Hume was among the leaders of the non-violent political alternative.
His popularity in Derry was confirmed when in 1969 he defeated the Nationalist Party leader, Mr Eddie McAteer, to become a Stormont MP. As the conflict became more violent and bloody through the early 1970s, he assisted in the emergence of the SDLP as the leading political voice of the North's Catholics.
His personal political standing rose steadily throughout the 1970s even as politics stagnated. When the Sunningdale power-sharing experiment collapsed in 1974 many in the SDLP found it difficult to achieve any political profile. However Hume assiduously continued to build links with senior Irish American politicians while becoming deputy leader of his party and, in 1979, leader in succession to Mr Gerry Fitt. In the same year he was elected an MEP for the first time, his 140,622 first preference votes confirming him as the undisputed leader of nationalist opinion in the North.
The international stature he developed through membership of the European Parliament and frequent visits to the US put paid to attempts by the British government and Sinn Fein to ensure their position on Northern Ireland prevailed. On the one hand he campaigned in the US against Noraid, ensuring Americans knew that the majority of northern nationalists did not support the IRA. On the other hand he ensured that the British government position that the North was purely an internal British problem was not accepted abroad.
Sinn Fein's entry into electoral politics in the wake of the 1981 H-block hunger strikes posed a major challenge to the SDLP's pre-eminent position. In June 1982 Mr Hume proposed the establishment of the New Ireland Forum which became the forum in which constitutional nationalism discussed how to proceed. The Sinn Fein threat was emphasised by its 10 per cent vote in the October 1982 Northern Ireland Assembly elections.
In the wake of Mrs Thatcher's famous "out, out, out" rejection of the Forum's proposals came the Anglo-Irish Agreement of 1985. Negotiated by Dr Garret FitzGerald's Fine Gael/Labour Coalition, Mr Hume was regularly consulted and the agreement was heavily influenced by his outlook.
Three years later, in 1988, Mr Hume had a series of discussions with the Sinn Fein president, Mr Gerry Adams, but these talks ended inconclusively. In early 1993 - and possibly before then - he privately resumed that dialogue, convinced that the republican movement was open to political activity as an alternative to violence.
He persevered with those talks despite extraordinary vilification from some politicians and commentators. The Hume/Adams contact had begun in January 1988, at the instigation of the Rev Alex Reid from Belfast's Clonard Monastery.
The dialogue with the Sinn Fein leader represented an enormous personal political risk. When news of it emerged in 1993, the Taoiseach, Mr Albert Reynolds, and Tanaiste, Mr Dick Spring, made it clear that Mr Hume had been acting on his own without Dublin's knowledge. Some Dublin politicians and commentators questioned Mr Hume's judgment. He was personally shaken by the abuse he received over this period from some politicians and newspapers, North and South. He maintained he didn't care "two balls of roasted snow" about the criticisms, but he did.
However, his talks with Mr Adams produced a joint peace strategy involving talks on the future of Northern Ireland after a ceasefire. Mr Hume impatiently urged the two governments to seize the opportunity, and in mid-December 1993 the British Prime Minister, Mr Major, and the Taoiseach, Mr Reynolds, issued the Downing Street Declaration.
A lengthy period of Sinn Fein prevarication ensued in 1994 with Mr Adams calling for "clarification" of the Declaration. Even among Mr Hume's supporters there were doubts about whether the strategy would pay off. Within the SDLP complaints surfaced that Mr Hume did not consult his party, or even tell them what he was at times. Even since the 1994 ceasefire was announced, some in the SDLP have complained that by bringing Sinn Fein's leaders into the political mainstream, Mr Hume has cultivated the greatest threat to the SDLP itself.
The 1998 Nobel Peace Prize, which he won jointly with Mr David Trimble, was the highest profile of a long series of prizes and awards he won down the years. Since then Mr Hume has scaled down his political involvement. He stepped back when the new political institutions were formed, allowing for the election of his deputy Mr Seamus Mallon as the North's deputy First Minister. He resigned his seat in the new Assembly last year and yesterday announced his retirement as party leader.
His announcement came as efforts continue to stabilise the political institutions that emerged from the peace process, and to scale down and eliminate paramilitary arsenals. The process is far from complete, but Mr Hume's famous three relationships - set out in his single transferable speech - still form the basis of all efforts to reach lasting political accommodation.