Britain's first woman ambassador to Ireland, Dame Veronica Sutherland, completes almost four years in the role with her last official engagement in Dublin today.
As she prepares to take up the post of Deputy General Secretary of the Commonwealth, the Taoiseach, Mr Ahern, last night said: "During her tenure she maintained a particular focus on the resolution of the problem of Northern Ireland.
"Through her own personal commitment, she played a significant role in that process to date."
In an RTE interview yesterday Dame Veronica expressed concern at the slow progress in the peace process.
"I read in the London Times this morning stories about no decommissioning and so on and I worry very much indeed. It does seem to me that we've all come a very, very long way but we still, all of us, have got a long way to go . . .
"So, yes, I do leave with concerns and I shall watch from England very carefully."
Close relations between the Taoiseach and the Prime Minister, Mr Blair, meant that the role of the British ambassador had changed. There was a sense that the work normally performed by the ambassador was being done directly on the telephone between the two prime ministers. "But I'm kept informed. I know what's going on," she added.
While nothing would give her greater pleasure in her new posting than welcoming Ireland into the Commonwealth, Dame Veronica said she would remain diplomatic and say that, in the end, it was a decision for the Government.
However, it would be "a good thing" for both the Commonwealth and Ireland if a decision was made to join.
Born in York in 1939, she became junior secretary to the late Airey Neave MP, but went on to study for an MA in German in Southampton. In 1965 she joined the Foreign Office and held posts in Delhi, London and Paris; she became head of the security department in 1984.
In 1994 she put her name on the list of candidates for Dublin. When she got the job she was, she said, "optimistic about peace".
Meanwhile a Dublin property developer, Mr Michael Cotter of Park Developments, has completed contracts for the purchase of Glencairn, the official residence of the British ambassador, on 35 acres at Sandyford, Co Dublin. The purchase price was slightly over £26 million.