The President Mrs McAleese and the Taoiseach Mr Ahern have joined other world leaders in paying tribute to Queen Elizabeth the Queen Mother who died yesterday aged 101.
British prime minister Mr Tony Blair said that the Queen Mother had been a symbol of Britain's "decency and courage".
The Archbishop of Canterbury Dr George Carey, said: "We are all the poorer because this gracious lady has been taken from us.
"Her unfailing dignity, devotion to duty and charm have been a precious part of our national life for as long as most of us can remember," he said.
Conservative Party leader Mr Iain Duncan Smith, said the Queen Mother was adored all over. "We will all miss her enormously because she was the best of us all," he said.
The head of the Catholic Church in England and Wales Cardinal Cormac Murphy O’Connor said people of all faiths would mark her death. "The Queen Mother bore the virtues so beloved by the British people: courage and steadfastness especially throughout the Second World War."
US President George W. Bush said he was "deeply saddened by her death". Canadian Prime Minister Jean Chretien echoed his words. "Above all, she will be remembered for her matchless and galvanising devotion to duty during the darkest hours of World War Two, when Britain, Canada and the Commonwealth stood alone against a seemingly invincible tyranny."