Are Muslim men allowed to take "sex slaves?"
As stated in the above answer there are only two ways a free person can be enslaved.
It's if they become prisoners of war or if they are born to slave parents.
https://en.m.wikipedia.org/wiki/Devshirme
And from the above link what appears to be the case is that Ottoman Empire had this system of enslaving free dhimmis which as far as I know is not allowed in Islam.And many western writers did say it was not allowed but I wanted an scholarly view on this matter from an Islamic scholar.
Was this matter allowed in Islam or was it prohibited but Ottomans did it anyway?