Khālid b. Yazīd (d. 85/704 or 90/708-9) was allegedly the first Arab alchemist. He was the second son of the Umayyad caliph Yazīd b. Muʿāwiya (r. 60-4/680-3) by his wife Fākhita. His date of birth is not usually given in the sources, but it is likely that he was still a teenager in 64/684. Ullmann has argued that he was born c. 48/668 (Ullmann, Ḫālid , 195). Sources give two different years for his death: 85/704 and 90/708-9. The earlier