Bohdan Khmelnytsky

Zynoviy Bohdan Mykhailovych Khmelnytsky of the Abdank coat of arms (c. 1595 – 6 August 1657) was a Ruthenian nobleman and military commander of Zaporozhian Cossacks as Hetman of the Zaporozhian Host, which was then under the suzerainty of the Polish–Lithuanian Commonwealth. He led the Cossacks to victory in a successful uprising against the Commonwealth and its magnates (1648–1654) that resulted in the creation of an independent Cossack state in Dnieper Ukraine.

In 1648–1649, the Cossacks under Khmelnytskyi's leadership massacred tens of thousands of Poles and Jews, with more handed over as yasir (slaves) to his Crimean Tatar allies, one of the most traumatic events in Polish and Jewish history. Under his rule of the newly established Cossack state, the massacres continued until at least 1652 and possibly led to hundreds of thousands of deaths, with the goal of eradicating non-Orthodox Ruthenian populations. In 1654, Khmelnytsky concluded the Treaty of Pereiaslav with the Russian Tsar and allied the Cossack Hetmanate with Tsardom of Russia, thus placing Ukraine under Russian protection.

Khmelnytsky's uprising permanently changed the balance of power in Europe and would play a significant role in the development of Ukrainian nationalism. In Western Europe, Khmelnytsky was compared to his rebel contemporary, Oliver Cromwell. Among Ukrainians, Khmelnytsky has been lauded as a folk hero and defender of the Orthodox faith, as well as a fighter for Ukrainian independence and founder of the first Ukrainian state; Russian imperial and Soviet propaganda meanwhile promoted him as a "unifier" of Ukraine with Russia. However, even among his compatriots Khmelnytskyi's image remained controversial due to his questionable alliances and harsh policies, which caused the death and enslavement of numerous people.