premise: Fidel Castro worked for the President of Cuba.
hypothesis: With the 2006 -- 2008 Cuban transfer of presidential duties , the Cuban presidential powers and duties were passed on from President Fidel Castro to the first vice president , his brother Raúl Castro , following Fidel 's operation and recovery from an undisclosed digestive illness believed to be diverticulitis . Fidel Alejandro Castro Ruz ( [ fiˈðel aleˈhandɾo ˈkastɾo ˈrus ] ; August 13 , 1926 -- November 25 , 2016 ) was a Cuban revolutionary and politician who governed the Republic of Cuba as Prime Minister from 1959 to 1976 and then as President from 1976 to 2008 . After participating in rebellions against right-wing governments in the Dominican Republic and Colombia , he planned the overthrow of Cuban President Fulgencio Batista , launching a failed attack on the Moncada Barracks in 1953 .