Klitschko brothers 5 months & 13 days. Vitali retained the WBC Heavyweight Championship until 15 December 2013, relinquishing his belt in pursuit of his political aspirations in his native Ukraine. The Klitschko brothers jointly run the professional boxing promotion companies ""K2 Promotions"" and ""K2 East Promotions"", as well as the ""Klitschko Brothers Fund"", a charity organization. They appear together on German TV shows and commercials, have a website shared between them, and support each other's training and fights. After Vitali's retirement, Wladimir continued to reign as champion & successfully defend all remaining title belts except for the WBC belt. He eventually lost
Vitali Klitschko vs. Dereck Chisora later. Chisora had been chasing a fight with Vitali's fellow world champion and brother Wladimir, and with that fight scheduled to happen on 11 December 2010, Klitschko pulled out just days prior with a torn abdominal muscle. The rescheduled fight for 30 April 2011 was also cancelled so [Wladimir] Klitschko could fight David Haye on July 2. With [Vitali] Klitschko due to fight Adamek, this left Chisora with no other option than to face his mandatory challenger for the British title, the upcoming Tyson Fury. Chisora's 14-0 win streak ended at the hands of the undefeated Fury, who won via