Almost immediately after it returned to Baghdad, in January 803, the Abbasid court witnessed the abrupt fall of the Barmakid family from power.
He was the mathematician and astronomer at the Abbasid court of the Caliph Harun al-Rashid.
Ibrahim Mûsili and Is'haq Mûsili were considered among the greatest musicians of the Abbasid court.
In return, Samonas manipulated his father, Andronikos Doukas, into rebelling and fleeing to the Abbasid court in 906/907.
The Abbasid court recruited Turkish slaves to serve as military officers, and Tulun did well for himself, eventually coming to command the Caliph's private guard.
Ibn Ṭūlūn used his influence at the Abbasid court to work against Ibn al-Mudabbir, and finally was able to have him removed after four years.
In the meantime, Hasan became involved in the intrigues of the Abbasid court.
Perhaps his most famous book is the Rusum dar al-khilafa which is a manual for behavior and work in the Abbasid court of late Buyid Baghdad.
He also invited delegations of scholars from India and other places to share their knowledge of mathematics and astronomy with the young Abbasid court.
After reaching the highest military ranks, a palace conspiracy forced him to seek refuge in the Abbasid court in 829.