Fidel Castro, who has been in charge of Cuba since he led a communist revolution in 1959, handed over his job to his brother, Raul, in July 2006 because he was about to undergo intestinal surgery.
In December of last year, Fidel Castro had suggested that he might possibly relinquish his role to make way for a younger successor, and he said at the time "my primary duty is not to cling to any position".
Fidel Castro’s letter, published on Granma's website in the night, explained that the Cuban leader would not accept another five-year term as president due to his recent ill health.
The National Assembly of Cuba is now expected to elect 76-year-old Raul Castro as Fidel Castro’s successor.
