Sen. Edward M. Kennedy of Massachusetts, a son of one of the most storied families in American politics, a man who knew triumph and tragedy in near-equal measure and who will be remembered as one of the most effective lawmakers in the history of the Senate, died late Tuesday night. He was 77.

The death was announced early this morning in a statement by the Kennedy family.

"Edward M. Kennedy -- the husband, father, grandfather, brother and uncle we loved so deeply -- died late Tuesday night at home in Hyannis Port," the statement said. "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. 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. ...He always believed that our best days were still ahead, but it's hard to imagine any of them without him."

Kennedy had been in precarious health since he suffered a seizure in May 2008 at his home in Hyannis Port, Mass. His doctors determined the cause had been a malignant glioma, a brain tumor that often carries a grim prognosis. Kennedy was the last surviving brother of a generation of Kennedys that dominated American politics in the 1960s and that came to embody glamour, political idealism and untimely death.