Undisputed champion he was still described as "undisputed champion" by some reports. After Joe Calzaghe's super middleweight victory over Mikkel Kessler in November 2007, he was frequently described as "undisputed champion". Others disputed this, because although he held the WBA, WBC, and WBO belts, he vacated his IBF title in November 2006 rather than face a mandatory challenger, and immediately vacated other titles as well. The unified champion is defined as a boxer that holds at least two world championships of major sanctioning bodies (WBA, WBC, WBO or IBF) in their respective division. Around 2004, the World Boxing Association recognized three different
Undisputed champion of coordinated bouts in 1986 and 1987, with Mike Tyson emerging as the first undisputed champion (WBC, WBA & IBF) since Leon Spinks in 1978. The title was split again in 1992 when Riddick Bowe forfeited the WBC title. Another major sanctioning body, the World Boxing Organisation, was established in 1988 in San Juan, Puerto Rico by a group of local businessmen. At the beginnings, when most of the challengers for WBA, WBC and IBF titles were Americans, WBO had a wider variety of countries, mainly European, represented in title bouts. Before the Klitschko Era, United Kingdom tied USA for