…Haditha shortly before his mysterious death in September 786, which may have been a murder.

Al-Tabari notes varying accounts of this death, e.g.

an abdominal ulcer or assassination.

Rumor suggests that al-Khayzuran was behind al-Hadi's death, because he had resisted her domination.

Al-Tabari (v. 30 p. 42f) notes al-Hadi's assertion of independence from his mother, his forbidding her further involvement in public affairs and his threatening the succession of his younger brother, who is at first imprisoned and soon is released to assume the caliphate.

Harun ar-Rashid thus becomes caliph on September 14, 786, succeeding to the rule of an empire reaching from the western Mediterranean to India.

He makes Yahya his vizier, or chief minister.

With Yahya are associated his sons al-Fa'l and Ja'far, for the vizier at this period is not only an initiator of policy but also has attached to himself a corps of administrators to carry out his decisions.

Al-Khayzuran will have a considerable influence over the government until her death in 789.