The Mongol Empire (1206-1368) had a tremendous impact on slavery across Eurasia.
While slaves played a minor role in pre-Imperial Mongolia, the Mongols saw people as a resource, to be distributed among the imperial family and used for imperial needs, like material goods.
This view created a whole spectrum of dependency running from free men to full slaves.
More specifically, the huge conquests of the United Empire (1206-60) resulted in huge supply of war captives, many of whom eventually sold in the Eurasian slave markets.
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Slavery in ancient Rome played an important role in society and the economy.
Besides manual labour, slaves performed many domestic services and might be employed at highly skilled jobs and professions.
Accountants and physicians were often slaves.
Slaves of Greek origin in particular might be highly educated. Unskilled slaves, or those sentenced to slavery as punishment, worked on farms, in mines, and at mills.