Irish Taoiseach Enda Kenny said Margaret Thatcher was "a formidable leader" who "defined an era in British public life."
He said: "Mrs Thatcher was a formidable political leader who had a significant impact on British, European and world politics. During her 11 years as prime minister, she defined an era in British public life.
"While her period of office came at a challenging time for British-Irish relations, when the violent conflict in Northern Ireland was at its peak, Mrs Thatcher signed the Anglo-Irish Agreement which laid the foundation for improved North-South cooperation and ultimately the Good Friday Agreement.
"I extend my deepest sympathies to her family and the Prime Minister David Cameron."
More top news
Islamic State poses as great a threat to Britain as the IRA during its bombing campaign in the 1970s, a watchdog has said.
Turning colder with showers in the west and windy for many, with severe gales in exposed northern and western parts.
The elderly woman's son complained to the council that his mother had been deprived of her liberty in an 'unprecedented' legal case.