Nowhere outside of America has the Kennedy legacy been more deeply felt than in Ireland, where photographs of the family adorn homes and hundreds claim to be distant relations of the glittering dynasty that brought the first Roman Catholic to the White House.
Here, Senator Edward Kennedy is largely known as JFK's brother. But he was also a power broker who mobilized Irish Americans and their political views on Northern Ireland — a kingmaker whose actions in the years before the Good Friday peace talks served to lay the groundwork for a lasting accord.
"He lived to see two great chasms bridged, between Catholic and Protestant in Northern Ireland and between black and white in his own United States," former Irish Prime Minister Bertie Ahern said. "These achievements, which were the dreams imagined by his brothers in his youth, were the legacy of a long life and of a good and great man."
Kennedy's family had strong links to Ireland — and to Britain. His father Joseph Kennedy served as ambassador to the Court of St. James. His sister, Jean Kennedy Smith, worked as the U.S. envoy to Ireland for five years under Bill Clinton.
Initially a strong supporter of the Irish nationalist cause, Kennedy was a key American promoter of the peace process, urging Britain to negotiate with the IRA-linked Sinn Fein party, and also reaching out to Protestant Unionists.
David Owen, who served as British foreign secretary in the 1970s, said Kennedy put his weight behind peace in Northern Ireland even at the risk of alienating powerful Irish-American allies whose sympathies lay with the province's Catholic Irish nationalists rather than the British Protestant majority.
"His influence on the peace process, and his influence on successive American presidents was I think absolutely crucial, and in particular of course on President Clinton," Owen told the BBC.
Martin McGuinness, formerly an Irish Republican Army commander and now the senior Catholic in Northern Ireland's power-sharing administration, told the broadcaster that despite disagreements he had "always respected" the senator, saying that "he understood what was required for the conflict to be resolved."
At a Dublin pub, 69-year-old Gerry Keating said Kennedy's role in the peace process made him "a good man."
"He was a great friend of this country," Keating said.
The senator from Massachusetts inspired praise from leaders of nations and campaigners for human rights, and many expressed sadness at learning of his death Tuesday from a brain tumor.
U.N. Secretary-General Ban Ki-moon praised Kennedy for "keeping and upholding the ideals and goals of the United Nations" and said his work "will be long remembered in the minds and in the hearts of many people, particularly vulnerable people, and those people whose human rights have been abused."
"He had been the voice of the voiceless and the defender of many defenseless people," Ban told reporters at U.N. headquarters in New York.
In Britain, where Kennedy received a knighthood earlier this year, he was praised for his indefatigable work on causes such as health care and judicial reform. Prime Minister Gordon Brown said that, "even facing illness and death, he never stopped fighting."
Achmat Dangor, CEO of the Nelson Mandela Foundation in South Africa, said Kennedy had been "a champion of democracy and civil rights."
"He made his voice heard in the struggle against apartheid at a time when the freedom struggle was not widely supported in the West," the foundation said. "We remain grateful for his role." South African President Jacob Zuma sent his "sincerest condolences."
In Australia, Prime Minister Kevin Rudd said Kennedy "made an extraordinary contribution to American politics." German Chancellor Angela Merkel voiced "deep sorrow" at his death. In Italy, President Giorgio Napolitano said Kennedy "deserves the homage of all the free world."
It was in the country that lionized his family that his work left perhaps its most lasting legacy. Nigel Baker, director of the American Institute at Oxford University, said Kennedy worked for a long time in Northern Ireland with other Irish American legislators to find common ground — despite the unwillingness of some in the Unionist and Republican communities to engage in dialogue.
"Much of the work he did was behind the scenes," Baker said. "But he was remarkably effective in building bridges there, as he was in the United States. He did a lot of work in private conversation with key players in Northern Ireland politics and I suspect that his role in Northern Ireland is probably more important in the long run than is generally acknowledged."
One of Kennedy's key moves in the peace process came when the United States was considering a visa for Gerry Adams, the leader of Sinn Fein, the political wing of the Irish Republican Army.
By the end of 1993, the IRA was signaling it would be prepared to end its violent campaign. Political leaders like Kennedy gambled that bringing Adams to the U.S. would help bring about a cease-fire. Clinton was persuaded — and the gamble became a breakthrough, with a cease fire in August 1994.
"What he managed to do, long before the 1990s, was bring together successful Irish Americans and get them involved in what he would regard as a more constructive approach to northern Irish politics," said Michael Cox, a professor of international relations at the London School of Economics.
The Good Friday accord came into force in 1998. As the years dragged on, the painstakingly negotiated deal began to fall apart when the IRA refused to renounce crime or to permit photos of its disarmament.
The group was accused of mounting the world's largest bank robbery, taking part in the slaying of a Catholic man, Robert McCartney in Belfast and laundering millions annually in criminal proceeds.
Kennedy put his foot down, refusing to meet with Adams when he traveled to the United States in 2005 to seek support from Irish-American activists.
The signal, combined with other high-profile slights, was unmistakable. Sinn Fein was deeply embarrassed because of Kennedy's stature. Faced with losing support among Irish Americans, they began again to participate in the peace process.
"I wouldn't underestimate the importance of the Irish American opinion in the peace process." said Adrian Guelke, professor of comparative politics at Queen's University Belfast.
Associated Press Writers around the world contributed to this report.