The Cossack leader Bogdan Chmielnicki (1595-1657) led the Dnieper Cossacks in the Ukrainian war of liberation against Polish rule in 1648.

Bogdan Chmielnicki, or Khmelnitskii, was born in Pereyaslav in the Polish-controlled Ukraine. His father was a registered Cossack and proprietor of a small farm and flour mill at Czehrin near the Dnieper River. Bogdan was educated in the school of one of the Orthodox brotherhoods and also studied at the Jesuit school in Yaroslav.

When his father died, Chmielnicki assumed management of the small family estate. He ran into difficulty, however, when a Polish lord claimed ownership of the land. Chmielnicki was summoned before a tribunal and dispossessed of his small estate. He eventually fled to the south, where he joined the Zaporozhan Cossacks. Anxious for revenge, Chmielnicki raised an army from among the Cossacks, and he also gained wide support from the Crimean Tatars and the oppressed...