Slavery in the Ottoman Empire was a legal and significant part of the Ottoman Empire's economy and society. The main sources of slaves were war captives and organized enslavement expeditions in North and East Africa, Eastern Europe, the Balkans and Circassia in the Caucasus. It has been reported that the selling price of slaves fell after large military operations. Enslavement of Caucasians was banned in the early 19th century, while slaves from other groups were allowed. In Constantinople (present-day Istanbul), the administrative and political center of the Empire, about a fifth of the population consisted of slaves in 1609. Sixteenth- and 17th-century customs statistics suggest that Istanbul's additional slave import from the Black Sea may have totaled around 2.5 million from 1450 to 1700.
Even after several measures to ban slavery in the late 19th century, the practice continued largely unabated into the early 20th century. As late as 1908, female slaves were still sold in the Ottoman Empire.Sexual slavery was a central part of the Ottoman slave system throughout the history of the institution.
A member of the Ottoman slave class, called a in Turkish, could achieve high status. Harem guards and janissaries are some of the better known positions a slave could hold, but slaves were actually often at the forefront of Ottoman politics. The majority of officials in the Ottoman government were bought slaves, raised free, and integral to the success of the Ottoman Empire from the 14th century into the 19th. Many officials themselves owned a large number of slaves, although the Sultan himself owned by far the largest amount. By raising and specially training slaves as officials in palace schools such as Enderun, the Ottomans created administrators with intricate knowledge of government and fanatic loyalty.