World Heavyweight Championship timeline:
Before the films
- 1922-1926: Jack Dempsey (lost to Gene Tunney)
- 1926-1928: Gene Tunney (title vacated)
- 1930-1932: Max Schmeling (lost to Jack Sharkey)
- 1932-1933: Jack Sharkey (lost to Primo Carnera)
- 1933-1934: Primo Carnera (lost to Max Baer)
- 1934-1935: Max Baer (lost to James J. Braddock)
- 1935-1937: James J. Braddock (lost to Joe Louis)
- 1937-1949: Joe Louis (title vacated)
- 1950-1951: Ezzard Charles (lost to Jersey Joe Walcott)
- 1951-1952: Jersey Joe Walcott (lost to Rocky Marciano)
- 1952-1956: Rocky Marciano (title vacated)
- 1956-1959: Floyd Patterson (lost to Ingemar Johansson)
- 1959-1960: Ingemar Johansson (lost to Floyd Patterson)
- 1960-1962: Floyd Patterson (lost to Sonny Liston)
- 1962-1964: Sonny Liston (lost to Cassius Clay)
- 1964-1970: Cassius Clay (title vacated)
- 1971-1973: Joe Frazier (lost to George Foreman)
- 1973-1974: George Foreman (lost to Apollo Creed in alternate "Rumble in the Jungle")
During the films
