The Taoiseach has this morning paid tribute to the outgoing leader of the Ulster Unionist Party David Trimble, saying, "his place in history is assured".
"I have greatly valued my relationship over many years with David Trimble. It is therefore with great regret that I heard he will be stepping down as leader of the Ulster Unionist Party."
Mr Trimble was one of the architects of the Belfast Agreement and was initially seen as the man who got the unionist community to recognise that the status quo in the North could not continue.
He took a considerable risk in first talking to Sinn Fein because of its link to the IRA and then co-operating in government with them. However, he was often blamed for blocking full implementation of the Agreement.
Today Mr Ahern acknowledged he was "a tenacious defender of the interests of the Unionist people" but the Taoiseach defended him as a man who "had the vision to work for the good of the broader community".
"The historic achievement of the Good Friday Agreement would not have been possible without him. He is owed an enormous debt of gratitude by everyone who shares a vision of this island reconciled and at peace.
"History will remember him as a man of courage who took risks for peace and who played a decisive role at a critical time in the history of Ireland .
"David Trimble's reputation as a leader of courage is known far beyond the politics of this island. His contribution was rightly recognised with the ultimate honour of the Nobel Peace Prize. He leaves an enormous and valuable legacy. His place in history is assured."