Taoiseach Micheál Martin has led the tributes to one of the principal architects of the Northern Ireland peace process, John Hume, who died this morning.
“John Hume was a great hero and a true peacemaker," Mr Martin said.
"Throughout his long life he exhibited not just courage, but also fortitude, creativity and an utter conviction that democracy and human rights must define any modern society.
“For over four decades, he was a passionate advocate for a generous, outward-looking and all-encompassing concept of nationalism and republicanism. For him the purpose of politics was to bring people together, not split them apart.
“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.
“While the 1998 Good Friday Agreement was the product of many people’s work, can anyone really claim that it would have happened without John Hume? He didn’t just talk about peace, he worked unstintingly for peace, at times in the face of the most virulent criticism and risk to his life. He knew that to be a peacemaker on this island meant being a risk-taker.
The Taoiseach also expressed his sympathy to Mr Hume's family.
President Michael D Higgins said that Mr Hume "transformed and remodelled politics in Ireland".
“All of those who sought and worked for peace on our island of Ireland, and in the hearts of all, will have been deeply saddened by the passing of John Hume, Nobel Peace Laureate and Statesman," he said.
"That his efforts were recognised through the awarding of the 1998 Nobel Peace Prize brought great joy not only to his people in Derry, his colleagues in politics, particularly in the SDLP, but to a wider global set of colleagues and fellow advocates for peace abroad who held him in the greatest esteem and admiration.
"Mar Uachtarán na hÉireann, as President of Ireland, may I say how deeply grateful we all should be that we had such a person as John Hume to create a light of hope in the most difficult of times."
Former Taoiseach John Bruton described him as a "pivotal figure" in the peace process - and in Irish history.
"He reframed the problem from being one about who held sovereignty over land, to being one about people, and how they related to one another," Mr Bruton said.
"Thus reframed, the issue became one to which violence and coercion became completely irrelevant. This was the intellectual basis of the peace process.
"In practical terms, he won the argument. That is why we have peace today."
Former Taoiseach Bertie Ahern also paid tribute to Mr Hume's contribution to Ireland.
Mr Ahern said: "50 years at the top of the game and 50 years of making a huge difference to current and future generations on the island of Ireland and that will be his legacy."
Tánaiste Leo Varadkar described Mr Hume as a "once in a generation leader".
"Any attempt to summarise John Hume’s contribution to the people of the island of Ireland is sure to fall short," he said.
“He leaves behind a legendary legacy of peace, progress and stability. His hard work and sacrifice will never be forgotten.
Former Ulster Unionist leader David Trimble, who was jointly awarded the Nobel peace prize along with Mr Hume, paid tribute.
“Right from outset of the Troubles, John was urging people to seek their objectives peacefully and was constantly critical of those who did not realise the importance of peace,” he said.
He recalled an incident after the Nobel prize ceremony in Oslo when the hotel the SDLP and UUP were staying in suggested they relaxed in two separate rooms.
“We didn’t do that, we relaxed and in some sense celebrated the occasion jointly, and that for me spelt out the principle for how we were going to proceed in the years after that,” he told BBC Radio Ulster’s Nolan Show.
Gerry Adams, former leader of Sinn Féin who held secret meetings with John Hume to begin the peace talks leading to the Good Friday Agreement said the process would never have happened without him.
Mr Adams said: "Many of the people who may be lauding John Hume today on the back of it breaking that he was talking to me wouldn't have given him the light of day, particularly those in the establishment at the time and in the establishment media.
"He was right, he wanted to go beyond talking about peace to make it happen and it wouldn't have happened when it did without John Hume."
Former British Prime Minister Tony Blair, who was in Number 10 when the Good Friday Agreement was signed, praised John Hume’s “epic” contribution to the peace process.
He said: “John Hume was a political titan; 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 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 who played a role in the peace talks that led to the Good Friday Agreement said he was "deeply saddened" by the passing of John Hume.
In a statement with his wife, former US Secretary of State and candidate for the US Presidency, Hilary Clinton, Mr Clinton said John Hume "kept marching on against all odds towards a brighter future for all the children of Northern Ireland".
Mr Clinton remembered visits to Derry with Mr Hume since the Good Friday Agreement was signed and praised his ability to compromise and humanity.
"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."