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 between 1880 and 1920. Once a consensus champion had been awarded the title, the championship could usually be taken only by beating the reigning holder, establishing a lineal championship. The New York State Athletic Commission (NYSAC) recognized champions from its foundation in 1920. The National Boxing Association (NBA) was founded by other U.S. state bodies in 1921, and began recognising champions in 1927. Until the 1960s, both usually recognised the same lineal champion. However, disputes could arise if the champion retired or moved to a different weight class. Occasionally, the International Boxing Union (renamed the European Boxing Union in 1946)