The Taoiseach has led tributes to the former British prime minister Lord Callaghan who died yesterday.
Mr Ahern said Lord Callaghan would be remembered for his good intentions and decency during some of Northern Ireland's darkest hours.
He said: "In this country, he will be particularly remembered for his visits to Derry at the height of the Troubles and he was of course, centrally involved both as Home Secretary and as Prime Minister in many decisions that had a profound impact on Northern Ireland.
"Despite the dark and turbulent times in Northern Ireland when he was in office, he will be remembered by many as a well-intentioned and decent man."
Lord Callaghan's death at his east Sussex home yesterday came just 11 days after his wife of 67 years, Audrey, passed away. He was the longest-living former Prime Minister and the only politician to have held all four major offices of state: Prime Minister, Chancellor of the Exchequer, Foreign Secretary and Home Secretary.
During his time as Home Secretary, Northern Ireland came centre stage as the campaign for Catholic civil rights gathered pace and violence erupted on the streets of Belfast and Derry. He was involved in the decision to deploy soldiers in Northern Ireland along with the then prime minister Harold Wilson in August 1969 following serious disturbances which saw many Protestant and Catholic families burnt out of their homes.
Lord Callaghan visited twice in August and October 1969 as electoral, housing and police reforms were implemented following the demand for Catholic civil rights.
Northern Ireland Secretary Paul Murphy said today Lord Callaghan had been an inspirational figure for many colleagues. "I had known Jim Callaghan for a quarter of a century and he was always kind and supportive of me personally as a fellow Welsh MP and later when I became a minister," he said.
"Jim Callaghan was a hugely inspirational figure who served his constituents of Cardiff South for 42 years and rose to hold the four great offices of state, Chancellor of the Exchequer, Home Secretary, Foreign Secretary and Prime Minister.
"He was a man of great honour, compassion and dignity. My thoughts and prayers are with his family."
Lord Callaghan was also fondly remembered by Democratic Unionist leader, the Reverend Ian Paisley, even if they did not always see eye to eye on Northern Ireland. The North Antrim MP said: "He was a decent man. "I certainly had a good personal relationship with him.
"When he was on the backbenches he was always keen to talk about Northern Ireland. He always wanted to find out what the Democratic Unionist Party's views were on it."
Nationalist SDLP leader Mark Durkan was more critical. While he acknowledged Lord Callaghan had made a positive intervention as Home Secretary in 1969 at the height of the civil rights campaign, the Foyle Assembly member said he should have abolished the unionist government at Stormont at that time.
"He was also the Prime Minister who stuck us with Roy Mason and his anti-political security agenda," Mr Durkan said. "Subsequent developments proved that there was much more that he could have done to develop Anglo-Irish relations.
"He was avuncular and apparently sincere, so it will always be a disappointment that on Ireland he did not act more, act better and act sooner."
PA