Fidel Castro has announced he’s stepping down as Cuban president, nearly half a century after leading the successful overthrow of a U.S.-backed dictatorship. Castro temporarily handed off power to his brother Raul Castro in July 2006 for health reasons. In a statement, Castro said: “It would betray my conscience to occupy a responsibility that requires mobility and the total commitment that I am not in the physical condition to offer.” He went on to say he will remain in public life as a writer and “soldier in the battle of ideas.” Castro has continued to pen regular columns during his illness. Cuba’s National Assembly is expected to nominate Raul Castro as a successor.