Mr Wilson became ill at his Enniskillen home yesterday morning and died soon after being taken to a local hospital.
Mr Wilson, 68, wrote a book, Marie, partly to help him to come to terms with the loss he and his wife Joan had suffered.
In the event fate only deepened Mr Wilson's suffering. Last December, his only son, Peter, was killed in a car crash.
In 1993, he returned to the limelight. In the wake of the Warrington IRA bomb in March 1993 that killed two boys, Timothy Parry and Jonathan Ball, he addressed public meetings in Dublin backing Dublin housewife Susan McHugh's simple but blunt assertion that the Irish Republic's people rejected IRA claims to be committing terror in their name. In February 1993, Mr Wilson, a Northern Ireland Protestant, was appointed an independent member of the Senate, Dublin's upper house of parliament, by the then Taoiseach, Albert Reynolds. The move was calculated to undermine partisan hostilities as the Irish prime minister pursued his breakthrough in the Downing Street Declaration, achieved 10 months later.
Last October, Mr Wilson joined the weekly forum for peace and reconciliation in Dublin Castle.
Tributes last night came from both sides of the Irish border. The Irish President, Mary Robinson, said his legacy would be "important and enduring".
Sir Patrick Mayhew, the Secretary of State for Northern Ireland, said that Mr Wilson was "a unique figure in public life" who held a reputation around the world as a man of integrity, Christian compassion and tremendous moral courage.Reuse content