DUBLIN — Garret FitzGerald, a beloved figure who as Ireland’s prime minister in the 1980s was an early architect for peace in neighboring Northern Ireland, died on Thurs., May 19, in a Dublin hospital, the government and his family announced. He was 85.

Flags were lowered to half staff as Irish politicians of all parties paid tribute to FitzGerald as a man of integrity and vision.

Britain’s Queen Elizabeth II, who was on the third day of her visit to Ireland, hailed FitzGerald as “a true statesman” who had “made a lasting contribution to peace.”

FitzGerald, former leader of Ireland’s perennial No. 2 party, Fine Gael, lived just long enough this year to see Fine Gael finally overtake its old enemy, Fianna Fail, to claim first place in a national election.

FitzGerald’s closest political colleagues said he was deeply heartened to see this week’s first-ever trip to Dublin by the queen, a crowning event of the Northern Ireland peace process that FitzGerald did much to promote during his two terms in office between 1981 and 1987.

“Garret was always burning with this desire for peace and reconciliation,” said Gemma Hussey, a former government colleague. “In a way, as he was slipping off, this was a wonderful week for him to go.”

“Garret was the Renaissance man of our time,” said Irish President Mary McAleese. “His thoughtful writing, distinctive voice, and probing intellect all combined to make him one of our national treasures.

“Above all, Garret FitzGerald was a true public servant. Steeped in the history of the state, he constantly strove to make Ireland a better place for all its people,” McAleese said.

FitzGerald’s greatest triumph was the Anglo-Irish Treaty of 1985 with Britain, an achievement shaped by his Dublin upbringing with a northern Protestant mother and southern Catholic father.

After suffering years of rebuffs, in 1985 he persuaded then-British Prime Minister Margaret Thatcher — renowned for her coolness to Irish nationalism — that she must concede a role for the Republic of Ireland in managing the north’s affairs for the first time.

The treaty infuriated the British territory’s Protestant majority but proved to be a game-changer for peace. It created a space where Ireland and the north’s Catholic leaders could begin to engage with both Britain and the north’s Protestants, culminating in the Good Friday peace accord of 1998.

“Sometimes he went down side alleys in discussions — and they could go on for hours,” said Irish Prime Minister Enda Kenny, who was a Fine Gael backbencher when FitzGerald was in power. “He had an eternal optimism over what could be achieved through politics.”