Leo d Hartog (1996)
Russia and the Mongol Yoke: The History of the Russian Principalities and the Golden Horde, 1221–1502
British Academic Press London & New York. (ISBN: ISBN 1-85043-961-3).
Slavery is mentioned in connection with the census or levies raised by the Mongol rulers in Russia from the thirteenth century (chapter 4, “The Batu-Berke Period: 1240-67”, esp. pp. 54-5 and 57-8). Slavery was the usual punishment for those who were unable to meet the demands. The violence associated with the collection of the taxes led to revolts.
According to Hartog, one of the reasons for the eventual decline of the Golden Horde was the depopulation of the region due to the fact that “to obtain capital, the people of the Golden Horde sold their children and close relatives as slaves, who were largely sent to Egypt” (chapter 6, “The Rise of Moscow and Lithuania”, p. 76). Generally, the slave trade is said to have “played a large role in the khanate’s economy” (chapter 8, p. 140).
In sum, the enslavement of people and drafting of skilled artisans resulted in a “permanent decline of a number of traditional crafts, which was undoubtedly the most destructive effect the Mongols had on urban life in Russia” (chapter 10, p. 163).