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
Heavyweight boxing championship records and statistics At the very beginnings, before the establishment of the sanctioning organizations, the title recognition passed through lineage in the fights under Marquess of Queensberry Rules. The champion was informally called "the man who beat the man". The fight between John L. Sullivan and Dominick McCaffrey is recognized by many boxing historians, including those at The Ring, to be for the inaugural World Heavyweight Championship under the Marquess of Queensberry Rules (however, some dispute that claim for various reasons, including the short distance of the bout, McCaffrey's small size and the fact that both fighters were Americans). The lineage was the