The main slave market was at Caffa which after 1475 belonged to the Ottoman Empire. The town had artillery and a strong garrison of Janissaries. Besides Caffa, slaves were sold in Karasubazar, Tuzleri, Bakhchysarai and Khazleve. Slave dealers came from various backgrounds: Turks, Arabs, Greeks, Armenians and others. For the right to trade they paid tax to the Crimean Khan and Turkish Pasha. In Caffa there were sometimes as many as 30,000 slaves, mostly from Muscovy and the southeastern lands of the Commonwealth. Habsburg diplomat and the ambassador of the Holy Roman Empire to Muscovy, Sigismund von Herberstein, wrote that "old and infirmed men, who will not fetch much at a sale, are given up to the Tatar youths, either to be stoned, or to be thrown into the sea, or to be killed by any sort of death they might please."
According to Ukrainian-Canadian historian Orest Subtelny, "from 1450 to 1586, eighty-six raids were recorded, and from 1600 to 1647, seventy. Although estimates of the number of captives taken in a single raid reached as high as 30,000, the average figure was closer to 3000…In Podilia alone, about one-third of all the villages were devastated or abandoned between 1578 and 1583."
Michalo Lituanus described Caffa as "an insatiable and lawless abyss, drinking our blood." Besides the bad food, water, clothing and shelter, they were subjected to exhausting labor and abuse. According to Litvin "the stronger slaves were castrated, others had their noses and ears slit and were branded on the forehead or cheek. By day they were tormented with forced labor and at night kept in dungeons." Muslim, Armenians, Jews, and Greek traders all purchased Slavic slaves in Caffa.