Heavyweight unification series Heavyweight unification series The heavyweight unification series, also known as the Heavyweight World Series, was a sequence of professional boxing matches held in 1986 and 1987 to crown an undisputed champion of the heavyweight class. The series was produced by HBO Sports and promoted by Don King. It ended with Mike Tyson as undisputed champion, holding the championship belts of the International Boxing Federation, World Boxing Association, and World Boxing Council. Prior to the series, the last undisputed heavyweight champion had been Leon Spinks, who won the championship in his 1978 victory over Muhammad Ali. Spinks had been stripped of
Billy Gibson (boxing) Billy Gibson (boxing) William J. Gibson (1876–1947) was a boxing promoter and manager for Benny Leonard (a former Lightweight champion), Gene Tunney (a former Heavyweight champion), Paulino Uzcudun, and featherweight Louis Kaplan. He was also the owner of the short-lived New York Brickley Giants of the National Football League. Gibson began his career in boxing as a promoter in Bronx. He teamed up with Leonard in 1914 and was his manager up until the 1917 lightweight championship. In 1923, Gibson became the manager of Tunney, who would go on to win the heavyweight title. Gibson retired in 1928. Gibson also