'McGuinness's refusal to live in past is a great lesson for us all' - Clinton leads the tributes
Former US president Bill Clinton has led international tributes to Martin McGuinness, who was described as "calm, courageous, and direct".
Friends and one-time enemies of the former IRA commander have remembered him as somebody who "played a defining role" in leading the republican movement away from violence.
Mr Clinton and his wife Hillary issued a statement in which they said Mr McGuinness's "integrity and willingness to engage in principled compromise" was invaluable.
Mr Clinton said his last memory of Mr McGuinness "will be the pride he took in his efforts to improve disadvantaged schools in unionist and Protestant communities".
"He believed in a shared future, and refused to live in the past, a lesson all of us who remain should learn and live by," he said.
Queen Elizabeth has not commented publicly on Mr McGuinness's passing, but Buckingham Place said she will be sending a private message to his family.
The monarch and the former IRA boss famously shook hands at a charity event in June 2012, an event which would once have been unimaginable.
President Michael D Higgins, who defeated Mr McGuinness in the 2011 presidential election, said his death left a gap that would be hard to fill.
"The world of politics and the people across this island will miss the leadership he gave, shown most clearly during the difficult times of the peace process, and his commitment to the values of genuine democracy that he demonstrated in the development of the institutions in Northern Ireland," President Higgins said.
Taoiseach Enda Kenny told the Dáil the former deputy first minister's passing represented "a significant loss to the wider political landscape on this island and beyond".
He said Mr McGuinness made a "remarkable political journey" and was one of the "architects of the Good Friday Agreement".
"His relationship with the late Ian Paisley was remarkable given the very different political background that they came from," Mr Kenny said. "His legacy of leadership will no doubt inspire the next generation of leaders in Northern Ireland."
Mr Paisley's son Ian Junior acknowledged many would have "mixed feelings".
The North Antrim MP said he had gone from viewing Mr McGuinness as the "godfather of the IRA" to considering him a personal friend.
"I think the Christian view in life is how a person's journey started is of course important, but it is how it finishes which is actually more important," he said.
British Prime Minister Theresa May said she could never condone the path he took "in the earlier part of his life" but added "Martin McGuinness ultimately played a defining role in leading the republican movement away from violence".
The former Sinn Féin leader's last action as a politician was to resign as deputy first minister in the Northern Assembly in a row over DUP leader Arlene Foster's involvement in a controversial renewable energy scheme. However, it emerged yesterday that Mrs Foster reached out to Mr McGuinness in recent days as his health deteriorated.
"Today's news will come as a shock to many people," she said, adding that history would record differing views on Mr McGuinness, but he had played a pivotal role in bringing the republican movement towards peace. Her predecessor Peter Robinson said the influence of Mr McGuinness will be greatly missed in the current talks on restoring devolved government to Belfast.
"The business of governing a divided society and coping with the endless curved balls that politics here brings tested both of us," he said.
"Yet while I knew his past, as he knew mine, we never doubted or gave up our shared commitment to create a new and better era in Northern Ireland politics. We had the best of personal relationships - keeping in touch even after my retirement and during his illness."
Sinn Féin's Mary Lou McDonald became emotional as she paid tribute to Mr McGuinness. She struggled to maintain her composure as she told TDs he was "an IRA volunteer, a risk taker, a hope giver".
Party leader Gerry Adams said: "Martin, as we all know, was a very passionate Irish republican. He believed in our people - that people of this island should be free."