Bohdan Zynoviy Mykhailovych Khmelnytsky (c. 1595 – 6 August 1657), was the Hetman of the Zaporozhian Host of the Crown of the Kingdom of Poland in the Polish–Lithuanian Commonwealth (now part of Ukraine). He led an uprising against the Commonwealth and its magnates (1648–1654) which resulted in the creation of a Ukrainian Cossack state. In 1654, he concluded the Treaty of Pereyaslav with the Tsardom of Russia.