Father Alec Reid has been hailed as a man of courage whose greatest legacy is the part he played in setting Northern Ireland on the path to peace.
The 82-year-old, one of the architects of the peace process, died peacefully in Dublin yesterday morning. His funeral will take place on Wednesday.
Last night tributes poured in for a man described as a chaplain to the peace process. Fr Reid facilitated secret talks between Sinn Fein and the SDLP and, when the IRA eventually decommissioned its weapons in 2005, helped witness the arms being put beyond use.
Rev Harold Good, who was part of the decommissiong team, said: "The genius of the man was that he enabled people to take steps and to trust themselves as well as others to embark on a journey that at one time to them would have been unthinkable."
Originally from Nenagh, Co Tipperary, Fr Reid joined the Redemptorist Order and went on to spend four decades based at Clonard Monastery in west Belfast.
Fr Reid, who had been in declining health, died at St Vincent's Hospital in Dublin at 6.40pm yesterday.
Archbishop Eamon Martin, coadjutor Archbishop of Armagh, said: "The first thing that came to mind when I heard the news was the gospel line: 'Blessed are the peacemakers, for they shall be called children of God'.
"Fr Reid was a model pastor although he, in his typical modesty, would probably be uncomfortable with such a title.
"His ministry was characterised by courage and he worked hard behind the scenes to build peace through patient and delicate negotiation.
"The people of this island will forever owe Fr Reid an immeasurable debt of gratitude for his tireless work towards building a civilisation of love and peace." Presbyterian Moderator Dr Rob Craig said Fr Reid was a regular visitor at Presbyterian churches along the Shankill Road to help build good relations with his neighbours.
"Without doubt he was a key influencer in bringing about the ceasefires and promoting an inclusive democratic peace process. For that we owe him an enormous debt of gratitude," he said.
The First and Deputy First Ministers led political tributes from both sides of the border.
Peter Robinson said: "Alec opposed violence and understood the key to making progress was through reaching out to others regardless of their background."
Martin McGuinness said Fr Reid played a crucial role in helping to initiate and build the peace process. "Fr Alec Reid was a man of great dignity and his service to society embodied decency and respect for everyone. He made an immeasurable contribution to the peace process and he has left a legacy of peace and hope for a better future for all," he said.
Mr Adams said Clonard Monastery, Fr Reid's base in west Belfast during the Troubles, was "the cradle of the peace process".
Mr Adams visited Fr Reid on Thursday and had been due to meet him again yesterday.
"I have known Fr Alec for 40 years. He was a man of deep conviction and love of the gospel who believed in the good of everyone," he said.
Mr Hume said Fr Reid was a pillar of the peace process. "Without his courage, determination and utter selflessness, the road to peace in our region would have been much longer and much more difficult to traverse," he said.
Irish President Michael D Higgins said Fr Reid would best be remembered for the courageous part he played in identifying and nurturing the early stages of the peace process.
Taoiseach Enda Kenny said: "Fr Reid made major contributions at so many critical times."
Fr Reid will be buried following a funeral Mass at Clonard Church on Wednesday.