The former boxer-turned-politician helped lead the Euromaidan protests that deposed President Viktor Yanukovych. As Ukraine prepared to form a new government, Klitschko reflected in February that it "will be based on key principles, professionalism and more qualities in the first turn. The economic situation is critical and we have a limited time of recovery."
On Thursday, Klitschko rededicated himself to creating better conditions for the citizens of Kiev through transparency and accessibility.
"I, Vitali Klitschko, assuming a position of Kyiv city mayor, swear: realizing my huge responsibility, that I will faithfully serve the community of Kyiv and the Ukrainian people, strictly abide by the Constitution and laws of Ukraine, protect the rights and freedoms and legitimate interests of citizens, and honestly perform my duties."
In addition to his political and athletic achievements, Klitschko counts actor and activist George Clooney among his friends. During the Euromaidan protests, Clooney lent his celebrity to the democratic movement by sending Vitali and his brother, Wladimir, a video-recorded message of solidarity, which they posted on their YouTube site.
Wladimir Klitschko had a cameo in Clooney's 2001 film Ocean's Eleven.