Fidel Alejandro Castro Ruz (born August 13, 1926) is the President of Cuba. After commanding the revolution that overthrew Fulgencio Batista in 1959, he held the title of Prime Minister of Cuba until 1976, when he became president of the Council of State as well as of the Council of Ministers. Castro became First Secretary of the Communist Party of Cuba in 1965, and led the transformation of Cuba into a one-party socialist republic. As president he also holds the supreme military rank of Comandante en Jefe ("Commander in Chief") of the Cuban armed forces. On July 31 2006, Castro, after undergoing intestinal surgery, transferred his responsibilities to the vice-president, his younger brother Raul.