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 his WBC title later that year because he opted not to fight against a mandatory challenger; the heavyweight championship had been fragmented ever since. This fragmentation and the resulting proliferation of title fights was seen by many as a discredit to the sport, and resulted in declining public interest in boxing. The idea of the series originated in October 1985, when Don King visited HBO Sports president Seth Abraham to propose a WBC title fight between Pinklon Thomas and Trevor Berbick. Abraham had little interest in the fight, but, inspired by the World Series that was being televised at the time, he suggested making the fight the first in a series to unify the heavyweight titles. King and Abraham mapped out the seven fights that would constitute the series, which King estimated could be produced for $20 million. King and HBO announced the series on January 17, 1986, during a press conference before a fight between Tim Witherspoon and Tony Tubbs. That fight was seen as an unofficial prelude to the series, as the winner would hold the WBA title and would participate in the series. The series would also include WBC champion Pinklon Thomas, IBF champion Michael Spinks, and top contenders from each of the three sanctioning bodies' rankings. The organizers were hopeful that Mike Tyson, then a young, fresh face, would qualify for the tournament and generate excitement for what was otherwise seen by some analysts as an unappealing slate of fighters.
Mike Tyson vs. James "Bonecrusher" Smith – March 7, 1987 at the Las Vegas Hilton – Tyson defeated Smith by unanimous decision to add the WBA title to his WBC title.
"Hard Road to Glory" – May 30, 1987 at the Las Vegas Hilton
* Tony Tucker vs. James "Buster" Douglas – Tucker defeated Douglas by technical knockout in ten rounds to claim the vacant IBF title
* Mike Tyson vs. Pinklon Thomas – Tyson defeated Thomas by technical knockout in six rounds to defend the WBA and WBC titles.
Mike Tyson vs. Tony Tucker – August 1, 1987 at the Las Vegas Hilton – Tyson defeated Tucker by unanimous decision to become the undisputed champion.
Aftermath
Michael Spinks had been stripped of his IBF title in the middle of the tournament because he had accepted a lucrative offer to fight Gerry Cooney, instead of facing his mandatory challenger, Tony Tucker. Spinks, however, was still recognized as the lineal champion and was also considered to be The Ring magazine heavyweight champion. Following the unification series, there were ongoing calls for Tyson, the champion of all three major sanctioning bodies, and Spinks, the lineal champion, to fight and erase any doubt about the identity of the "true" champion. In June 1988, the two champions faced off, and Tyson knocked out Spinks in 91 seconds. Tyson held on to his titles until February 1990, when he was knocked out by Buster Douglas. The titles remained unified until December 1992, when undisputed champion Riddick Bowe relinquished his WBC title.
