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 Vitali Klitschko Vitali Volodymyrovych Klitschko (; , ; born 19 July 1971) is a Ukrainian politician and former professional boxer. He currently serves as Mayor of Kiev and head of the Kiev City State Administration, having held both offices since June 2014. Klitschko is a former leader of the Petro Poroshenko Bloc and a former Member of the Ukrainian Parliament. He became actively involved in Ukrainian politics in 2005 and combined this with his professional boxing career until his retirement from the sport in 2013. As a boxer, Klitschko is a three-time world heavyweight champion, the second longest reigning WBC