Statesman Constantine Caramanlis, revered for helping restore Greece's democracy after military dictatorships, died of heart failure Thursday. He was 91.

Caramanlis died in the intensive care unit of an Athens hospital, after a viral infection set in following an April 12 heart attack.Caramanlis' health had been in decline since he retired in 1995 after his second term as president, ending a 60-year political career that included six premierships.

"The great leader who inspired Greece has passed into history," said Costas Caramanlis, a nephew and head of the main opposition conservative New Democracy party, founded by his uncle in 1974. "His vision will always lead us."

Caramanlis' tenure covered many of the nation's defining moments this century: the rise and fall of the monarchy; the Nazi occupation in World War II and the civil war that followed; the 1967-74 military junta and, finally, Greece's recognition as a full Western European ally.

He was often referred to as a "savior" of the nation for aiding in the restoration of democracy in 1974 after military rule.