SENATOR Edward Kennedy of Massachusetts, the last surviving brother in a political dynasty and one of the most influential senators in US history, died on Tuesday night at his home on Cape Cod after a year-long struggle with brain cancer. He was 77.

In nearly 50 years in the Senate, Kennedy served alongside 10 presidents - his brother John Fitzgerald Kennedy among them - compiling an impressive list of legislative achievements on health care, civil rights, education, immigration and more.

His only run for the White House ended in defeat in 1980. More than a quarter-century later, he handed then-Senator Barack Obama an endorsement at a critical point in the campaign for the Democratic presidential nomination, explicitly likening the young contender to President Kennedy.

To the American public, Kennedy was best known as the last surviving son of America's most glamorous political family, father figure and, memorably, eulogist of an Irish-American clan plagued again and again by tragedy.

Kennedy's death triggered an outpouring of superlatives, from Democrats and Republicans as well as foreign leaders.

"An important chapter in our history has come to an end. Our country has lost a great leader, who picked up the torch of his fallen brothers and became the greatest United States senator of our time," Presisent Obama said in a written statement.

Kennedy's family announced his death in a brief statement released early yesterday.

"We've lost the irreplaceable center of our family and joyous light in our lives, but the inspiration of his faith, optimism, and perseverance will live on in our hearts forever," the statement said. "We thank everyone who gave him care and support over this last year, and everyone who stood with him for so many years in his tireless march for progress toward justice, fairness and opportunity for all."

JFK's footsteps

Former First Lady Nancy Reagan said that her husband and Kennedy "could always find common ground, and they had great respect for one another."

Kennedy was elected to the Senate in 1962, taking the seat that his brother John had occupied before winning the White House, and served longer than all but two senators in history.

His own hopes of reaching the White House were damaged - perhaps doomed - in 1969 by the scandal that came to be known as Chappaquiddick, an auto accident that left a young woman dead.

He sought the White House more than a decade later, lost the Democratic nomination to President Jimmy Carter, and bowed out with a stirring valedictory that echoed across the decades: "For all those whose cares have been our concern, the work goes on, the cause endures, the hope still lives and the dream shall never die."

Kennedy was diagnosed with a cancerous brain tumor in May 2008 and underwent surgery and a grueling regimen of radiation and chemotherapy.

He made a surprise return to the Capitol last summer to cast the decisive vote for the Democrats on Medicare. He made sure he was there again last January to see his former Senate colleague Barack Obama sworn in as the nation's first black president, but suffered a seizure at a celebratory luncheon afterward.

He also made a surprise and forceful appearance at last summer's Democratic National Convention, where he spoke of his own illness and said health care was the cause of his life. His death occurred precisely one year later.

He was away from the Senate for much of this year, leaving Republicans and Democrats to speculate about what his absence meant for the fate of Obama's health care proposals.

Under state law, Kennedy's successor will be chosen by special election. In his last known public act, the senator urged state officials to give Democratic Governor Deval Patrick the power to name an interim replacement. But that appears unlikely, leaving Democrats in Washington with one fewer vote for the next several months as they struggle to pass Obama's health care legislation.

In a recent interview with The Associated Press, Kennedy's son, Rhode Island Democratic congressman Patrick Kennedy, said his father had defied the predictions of doctors by surviving more than a year with his fight against brain cancer. The younger Kennedy said that gave family members a surprise blessing, as they were able to spend more time with the senator and to tell him how much he had meant to their lives.

Kennedy political dynasty long marked by tragedy

The lives of Kennedy family members, noted for their extraordinary accomplishments, have also been plagued by tragedy. Following is a chronology of some of the misfortunes that befell the US political dynasty:

1941: Rosemary Kennedy, the oldest daughter of Joseph and Rose Kennedy, who was mentally disabled, was institutionalized for the rest of her life after a lobotomy reduced her abilities. She died in 2005.

1944: Joseph Kennedy Jr, the oldest of the nine Kennedy children, died at age 29 in a plane crash over the English Channel during World War II.

1948: Kathleen Kennedy Cavendish, the fourth of the Kennedy children, was killed in a plane crash in France at age 28.

1963: President John Kennedy was assassinated on November 22 while riding in a presidential motorcade with his wife in Dallas, Texas, at age 46.

1964: Senator Edward Kennedy narrowly escaped death in a plane crash that killed an aide.

1968: Senator Robert Kennedy was assassinated on June 5 in Los Angeles at age 42, just after he won California's Democratic presidential primary election.

1969: Edward Kennedy drove off a bridge on his way home from a party on Chappaquiddick Island in Massachusetts. An aide in the car with him, Mary Jo Kopechne, died in the accident.

1984: David Kennedy, a son of Robert, died of a drug overdose at age 28.

1997: Another of Robert Kennedy's sons, Michael, died in a skiing accident in Aspen, Colorado, at age 39.

1999: John Kennedy Jr along with his wife and sister-in-law were killed when the plane he was flying crashed in Massachusetts.

US President Barack Obama

"For five decades, virtually every major piece of legislation to advance the civil rights, health and economic well being of the American people bore his name and resulted from his efforts."

British Prime Minister Gordon Brown

"Senator Edward Kennedy will be mourned not just in America but in every continent. He led the world in championing children's education and health care, and believed that every single child should have the chance to realize their potential to the full."

Irish Prime Minister Brian Cowen

"In good days and bad, Ted Kennedy worked valiantly for the cause of peace on this island. Today, America has lost a great and respected statesman and Ireland has lost a long-standing and true friend."

Israeli Prime Minister Benjamin Netanyahu

"Senator Edward Kennedy has been a friend for 30 years, a great American patriot, a great champion of a better world, a great friend of Israel. He will be sorely missed."