Castro's retreat, like his rule, shrouded in secrecy

HAVANA (Reuters) - Cuban leader Fidel Castro has gone into retirement under the same shroud of secrecy that kept him alive as a guerrilla fighter and marked much of his 49-year rule.

Castro formally stepped down this week, saying he was not strong enough to return from the intestinal illness that forced him to provisionally hand power to his younger brother, Raul Castro, in July 2006.

But questions remain over the nature and seriousness of his condition, which has been a closely guarded state secret, and his whereabouts.

As a young revolutionary, the charismatic Castro spun a web of secrecy to frustrate his enemies and finally seize power in a 1959 revolution. Those precautions later helped him to survive numerous assassination attempts -- many of them plotted or backed by the CIA -- in the early years of his rule.

While Cuban leader, his overseas trips were never announced until he landed.

The location of his home was long a secret, though it is rumored to be in a residential compound -- referred to as Point Zero -- in the exclusive Siboney district of Havana.

Castro's private life is never discussed by government officials and never reported on by the state-run newspapers.

Cubans typically say they have "no clue" when asked about his family. Few know their veteran leader is married to Dalia Soto del Valle, a school teacher with whom he has five sons, all of them with names that start with the letter "A."

That aura of secrecy continued after he stood down temporarily in July 2006 after emergency surgery. He said the enmity of Washington justified treating his poor health as an issue of national security.

"Due to the plans of the empire, the state of my health has become a state secret, which can't constantly be made public," he said then.

He has told Cubans since then that the illness, whatever it might be, nearly killed him, but state-controlled media and government officials have told them little more.

A Spanish doctor visited Castro late in 2006 and hospital sources in Spain later told media there the Cuban leader had a severe intestinal infection after a botched operation.

Yet no details on what the illness is that turned him into a frail and shuffling old man have ever been published in Cuba, and Cubans do not know where he has been recovering.

Several foreign leaders who visited Castro in 2006 said they were taken to see him in a basement below the headquarters of the ruling Communist Party's central committee in Havana's Revolution Square.

He is now believed to be convalescing at or near the CIMEQ Hospital, a top medical facility for Cuba's nomenklatura in residential western Havana. But few people know for sure.

When he announced his retirement on Tuesday, Castro said he took the decision two months earlier and dropped a hint of his plans in a letter to a state television journalist in December.

"Not even the recipient of the message knew my intention," he wrote in the message announcing his retirement.

(Editing by Anthony Boadle and Kieran Murray)