After almost half a century in power, Cuba's Fidel Castro is stepping down.
He made the announcement overnight on the online edition of the Cuban Communist Daily paper Granma.
"I will neither aspire to nor accept the positions of president of the state council and commander in chief."
That means that for the first time since 1959, the 81-year-old will not be officially in charge in Cuba.
His brother Raul, 76, who has been acting president for his ailing brother, since July 2006, will be formally installed this weekend.
The world's longest-serving political leader is leaving on his own terms, having survived efforts by 10 U.S. presidents to bring him down, including a disastrous CIA-backed invasion in 1961 and a missile crisis that brought the world to the brink of nuclear war in 1962.
Deputy Secretary of State John Negroponte today said the transfer of power will have no effect on the decades-long U.S. embargo of Cuba. Asked whether Washington planned to change its Cuba policy now that Castro had stepped down, Negroponte said, "I can't imagine that happening anytime soon," The Associated Press reported.
In the summer of 2006 the fervently anti-Castro community of so-called Cuban exiles in Miami erupted in celebration with word that he was temporarily stepping aside because of failing health. He announced at the time that he had undergone intestinal surgery.
Since then a frail Castro has been seen only sporadically on video in meetings with leftist world leaders, but he has not been seen in public.
Which is why in Havana today it is life as usual. We reached Marc Frank, a journalist who lives in Havana.
"I think the Cuban people slowly, but surely have come to accept that Fidel Castro needs to retire, that he no longer is the man he was and that it's time to move on," Frank told ABC News from Havana this morning. "So I really don't see that there will be any surprise at all in this."
In his letter, Castro conceded he no longer has the strength to continue.
"My wishes have always been to discharge my duties to my last breath. That's all I can offer," Castro wrote, adding "But it would be a betrayal of my conscience to accept a responsibility requiring more mobility and dedication than I am physically able to offer. This I say devoid of all drama."
Taking over from Castro is his younger brother Raul, who has been second-in-command for the last 49 years and acting president since his brother's illness. The transition of power will be ratified at a meeting of the Cuban National Assembly, Sunday.
The biggest question may be, who will be Raul Castro's No. 2? The man designated to succeed Raul when he dies.
It is a momentous moment for the 11.2 million people of Cuba and for more than 1 million Cuban-Americans in the United States, but this is clearly not the way the Cuban exiles had hoped Castro's rule would end.
In many ways, this is the worst possible scenario for the Cuban exiles who have waited so long for Castro's rule to end. A peaceful transition means that the communist party will remain in power on the island and dramatic democratic change isn't likely anytime soon.
President Bush speaking to reporters during his visit to Rwanda echoed this sentiment.
"Eventually, this transition ought to lead to free and fair elections — and I mean free, and I mean fair — not these kind of staged elections that the Castro brothers try to foist off as true democracy," Bush said.
The end of Castro's rule will not bring an end to U.S. trade sanctions against the island nation. The U.S. sanctions law says they can't be lifted until there is no Castro of any stripe in power in Cuba.