PRESIDENT of Ireland Michael D Higgins led tributes from the Republic, saying Mr McGuinness’s death leaves a gap that will 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,” he said.
“He made an immense contribution to peace and reconciliation in the North.”
In a statement released this morning, his Sinn Fein party said: “It is with deep regret and sadness that we have learnt of the death of our friend and comrade Martin McGuinness who passed away in Derry during the night.
“He will be sorely missed by all who knew him.”
British Prime Minister Theresa May said Martin McGuinness made an “essential and historic contribution” to Northern Ireland’s peace process.
The Prime Minister said the former IRA commander “played a defining role” in leading the Republican movement away from violence. But Mrs May made clear she did not always “see eye to eye” with the former deputy first minister.
Sinn Fein president Gerry Adams paid tribute to his lifelong friend, saying: “Throughout his life Martin showed great determination, dignity and humility and it was no different during his short illness.
“He was a passionate republican who worked tirelessly for peace and reconciliation and for the reunification of his country.
“But above all he loved his family and the people of Derry and he was immensely proud of both.
“On behalf of republicans everywhere we extend our condolences to Bernie, Fiachra, Emmet, Fionnuala and Grainne, grandchildren and the extended McGuinness family.
During his time in office Mr McGuinness forged an unlikely friendship with then DUP leader Ian Paisley and the two earned the nickname the Chuckle Brothers.
Jo Berry, founder of Building Bridges for Peace, whose father Sir Anthony Berry died in the Brighton hotel bombing, said she valued Mr McGuinness as an “inspiring example of peace and reconciliation”.
Mr McGuinness’s successor as the party’s leader at Stormont, Michelle O’Neill, paid tribute.
She tweeted: “My heart is broke this morning. We have lost a legend, a giant of a man. I’m very proud to say he was my friend and mentor x.”
Former Prime Minister Tony Blair said: “I am very sorry to learn of Martin’s death and send his family my deep sympathy and condolences.
“Over the years – through the arduous negotiation of the Good Friday Agreement – and for the years after it, I got to know Martin well.
“By the time that extraordinary day arrived in 2007 after almost a decade of hard work where we could witness the – to my generation – incredible sight of he and Ian Paisley sitting down together in Government, the transition of Martin to reconciliator was complete.
“Whatever the past, the Martin I knew was a thoughtful, reflective and committed individual. Once he became the peace maker he became it wholeheartedly and with no shortage of determined opposition to those who wanted to carry on the war.
“I will remember him therefore with immense gratitude for the part he played in the peace process and with genuine affection for the man I came to know and admire for his contribution to peace.”