The Nobel Peace Prize winner and prominent Northern Ireland politician John Hume has died aged 83.
He died in a Londonderry nursing home following a long period of illness.
One of the highest-profile politicians in Northern Ireland for more than 30 years, he helped create the climate that brought an end to the Troubles.
He was a founding member of the Social Democratic and Labour Party (SDLP) in 1970 and led the party from 1979 until 2001.
Mr Hume played a major role in the peace talks, which led to the Good Friday Agreement in 1998.
He was widely admired for his steadfast commitment to peaceful, democratic politics during three decades of violence in Northern Ireland.
Tributes have been paid by political leaders past and present, including former Prime Minister Tony Blair, who was in office when the peace deal was signed.
Mr Blair said he was "a visionary who refused to believe the future had to be the same as the past".
"His contribution to peace in Northern Ireland was epic and he will rightly be remembered for it," he said.
"He was insistent it was possible, tireless in pursuit of it and endlessly creative in seeking ways of making it happen."
Former US President Bill Clinton said Mr Hume "fought his long war for peace in Northern Ireland"
"His chosen weapons: an unshakeable commitment to nonviolence, persistence, kindness and love," he said.
"With his enduring sense of honour, he kept marching on against all odds towards a brighter future for all the children of Northern Ireland.
"I'll never forget our night in Derry in 1995, with the town square and blocks around full of hopeful faces, walking with him across the Peace Bridge nearly 20 years later, and all of the moments we shared in between."
'Provided a compass'
Prime Minister Boris Johnson said Northern Ireland had "lost a great man who did so much to help bring an end to the Troubles and build a better future for all".
He said Mr Hume's vision "paved the way for the stability, positivity and dynamism of the Northern Ireland of today".
SDLP co-founder Austin Currie said "John Hume is the greatest Irishman since Parnell".
"His place in Irish history is richly deserved. Hume's consistency provided a compass through some terrible times," he said.
In the late 1980s, Mr Hume took considerable risks for peace by holding talks with the then leader of Sinn Féin, Gerry Adams.
The talks were controversial because the IRA was still heavily involved in violence, but Mr Hume's aim was to persuade republicans to commit to exclusively democratic means.
The Hume-Adams talks helped to lay the foundations for the 1994 IRA ceasefire and later negotiations which resulted in the Good Friday Agreement.
Mr Adams said he was "a political leader genuinely prepared to look at the bigger picture and to put the wider interests of society above narrow party politics".
He said his decision to meet him was a "breakthrough moment in Irish politics".
"When others were stuck in the ritual politics of condemnation, John Hume had the courage to take real risks for peace," he added.
Taoiseach (Irish Prime Minister) Micheál Martin hailed Mr Hume as "a true peacemaker".
"During the darkest days of paramilitary terrorism and sectarian strife, he kept hope alive. And with patience, resilience and unswerving commitment, he triumphed and delivered a victory for peace," he said.
Northern Ireland's First Minister Arlene Foster described the former SDLP leader as a "giant in Irish nationalism".
"In our darkest days he recognised that violence was the wrong path and worked steadfastly to promote democratic politics," the Democratic Unionist Party (DUP) leader added.
Following the 1998 peace deal, Mr Hume was awarded the Nobel Peace Prize, along with the then leader of the Ulster Unionist Party, David Trimble.
Lord Trimble said from the outset Mr Hume urged people to stick to their objective peacefully.
"He was a major contributor to politics in Northern Ireland, particularly to the process that gave us an agreement that we are still working our way through," he said.
"He will be remembered for that contribution for years to come."
'Legitimacy of the people'
Mr Hume spent decades fighting and winning elections to different parliaments at Stormont, Westminster and Brussels.
He served as member of the European Parliament (MEP) for more than 25 years, and held a seat in Westminster as MP for the Foyle constituency for almost 22 years.
Former Taoiseach (Irish Prime Minister) Bertie Ahern, who co-signed the 1998 peace deal with Tony Blair, said Mr Hume always "saw the bigger picture" in Irish politics.
He credited Mr Hume with the idea of ratifying the deal with different referenda on both sides of the Irish border.
"When the Good Friday Agreement was signed by Tony and I, he [Mr Hume] said: 'You put this to the people north and south and it will get the legitimacy of the people'.
"That was singularly his idea and it really was a bright idea," Mr Ahern told BBC Radio Five Live.
Irish President Michael D Higgins said Mr Hume had "remodelled politics in Ireland" and hailed his "personal bravery and leadership".
Northern Ireland Secretary Brandon Lewis said Northern Ireland would not be where it was today "without his leadership and courage".
"He dedicated his life to peace, and for that the people of Northern Ireland will never forget him," he said.
Sinn Féin leader Mary Lou McDonald described him as "a national icon".
Archbishop Eamon Martin said "a great sadness" had descended over the city of Derry.
The head of the Catholic Church in Ireland described Mr Hume as "a paragon of peace, a giant of a statesman whose legacy of unstinting service to the common good is internationally acclaimed".
There is no way you could overestimate John Hume's contribution in the political development of Northern Ireland.
He was definitely, during those years, the brains behind the approach to the peace process.
He worked on differing relationships, trying to solve problems which seemed for so many years to be completely without any possible solution.
He helped create the political space in which the different parties could manoeuvre their way towards what became the the Good Friday Agreement.
John Hume battled on at very hard times during the Troubles - when any kind of dialogue came under attack from opponents as being a sign of weakness.
He persevered with his efforts to bring about a solution.
Mr Hume died in the early hours of Monday at Owen Mor nursing home in Derry, having suffered dementia for several years.
His funeral Mass will be celebrated at the Cathedral of Saint Eugene, Derry, at 11.30 BST on Wednesday.
In a statement, his family said his loss would be greatly felt and they had drawn "great comfort" from "being with John again in the last days of his life".