High Quality Content by WIKIPEDIA articles! Rocky Marciano (September 1, 1923 – August 31, 1969), born Rocco Francis Marchegiano, was an American boxer and the heavyweight champion of the world from September 23, 1952, to April 27, 1956. Marciano is the only champion to hold the heavyweight title and go undefeated throughout his career. Marciano defended his title six times. He holds notable wins over Ezzard Charles and Joe Louis.