Khmelnytsky managed to overcome more than a century of mutual hostility between Cossacks and Tatars. He also turned the idea of Cossack as "protector of the Christian people" on its head by agreeing to pay the Khan of Crimea with jasyr or Christian captives. Initially these were Polish prisoners, but later whole tracts of land in Ukraine were assigned for Tatars to capture anyone (including Jews who moved "en masse" into the palatinates of Ukraine after 1569) and lead them to be sold on the slave markets of Kaffa.