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 (UDAR) and was elected into parliament for this party in 2012. He was a leading figure in the 2013–2014 Euromaidan protests, and he announced his possible candidacy for the Ukrainian presidency but later withdrew and endorsed Petro Poroshenko. He was elected Mayor of Kiev on 25 May 2014. Klitschko headed the election list of the winner of the 2014 Ukrainian parliamentary election, the Petro Poroshenko Bloc, but he gave up his parliamentary seat to stay on as Mayor of Kiev. On 28 August 2015 the UDAR party merged into Petro Poroshenko Bloc. Klitschko thus became the new party leader. Klitschko