Did the Ottomans have any sort of racial hierarchy akin to the castas in Latin America? Although the Ottomans enslaved many non-Muslim ethnic groups, I don't understand how or if they were placed into different roles in society, or how those with mixed race ancestry were viewed.
For example, concubines of the Sultan seem to have frequently been drawn from [ Eastern European christian populations ] ( https://en.wikipedia.org/wiki/List_of_consorts_of_the_Ottoman_sultans ). Were those descended from these consorts seen in any way as "less Turkish" due to their European ancestry? How were Africans seen? Although East Africans were often enslaved by the Ottomans, they seem to have been valued in particular as eunuchs, and there were no consorts of East African heritage. Was it somehow more acceptable for a Turk to have a mother from the Balkans or the Caucasus than from Africa?
Ottomans were much more tolerant of different religions, sects or races in comparison to other European Empires of the time like Spain, England or HRE. The practice of Devşirme or blood tax (a policy of forcibly taking young Christian boys from their families and taking them to the capital for education and an eventual career, either in the Janissary military corps or the Ottoman administrative system. Most of the children collected were from the Empire's Balkan territories) was objectionable if we see it in modern context but it created social opportunities for those children as most of them went on to become high officials in Ottoman court and elite Janissary Corp and many of these children returned to their lands as governors and state officials which brought social development to such areas. There weren't any policies of forced conversion except that children collected as blood tax mostly used to become Muslims due to their upbringing. As for other races Greeks were most powerful minority race and controlled most of business and merchant trade and many held high posts in Ottoman court. North African (mostly Egyptians) were seen as equals being Muslims. Tatars were strongest Vassals of Sultan and used to provide troops for many battles. Arabs were not united as an ethnicity at the time and were divided in different tribes with their own dealings with Ottoman governors. Caucasians were not treated as good and were often enslaved but they had higher social status than African slaves. Pagan Africans from Central Africa and great lakes were not treated good and were systematically enslaved. Persians were the enemies of Ottomans and both empires had many wars. Ottoman Empire though didn't share any land borders with India but the but the relations between Ottoman Empire and Mughal Empire of India were good and many Ottoman Admirals visited the Mughal court. Mughals recognized the claim to title of Caliph by Ottoman Sultan but they saw them as just another Muslim Empire like themselves.