Concubinage in the Muslim world was the practice of Muslim men entering into intimate relationships without marriage, with enslaved women,: "Concubines in Islamic society, with few exceptions, were slaves.

Concubinage in China traditionally resembled marriage in that concubines were recognized sexual partners of a man and were expected to bear children for him.

In classical Islamic law, a concubine was an unmarried slave-woman with whom her master engaged in sexual relations.