Yahya ibn Khalid
Yahyā ibn Khālid (Arabic: يحيى بن خالد) (died 806 CE) was a member of the powerful Persian Barmakids family, son of Khalid ibn Barmak. Around 765, he was appointed to Azerbaijan by the Caliph Al-Mansur. Yahya's son Fadl ibn Yahya was born at Ar-Reiy, at the same time as Caliph al-Mahdi's son Harun. Al-Mahdi entrusted Yahya in 778 with Harun's education.
When Al-Hadi was Caliph, Yahya dissuaded the Caliph several times from proclaiming his own son as heir instead of Harun. He eventually did so, and cast Yahya into jail, but died shortly after. When Harun became Caliph as Harun al-Rashid, he made Yahya Vizier. Under his influence, the Caliph invited to Baghdad many scholars and masters from India, especially Buddhists. A catalogue of both Muslim and non-Muslim texts prepared at this time, Kitab al-Fihrist, included a list of Buddhist works. Among them was an Arabic version of the account of Buddha’s previous lives, Kitab al-Budd.
He had three sons, among which Jafar succeeded him as Vizier, Musa ruled Damascus, and Fadl was governor of Khurasan, then of Egypt. In 803, his family fell into disgrace, and he was cast into prison, where he died in 806 (according to the story, because his son Jafar had an affair with Harun al-Rashid's sister, most likely because the family had too much power).