Harun’s capital at Baghdad, renowned for the magnificence of his court, has become a vigorous center of commercial activity.

The administration of the 'Abbasid empire has for more than sixteen years been mainly the responsibility of members of the priestly Barmakid family, who have provided the money for the luxury and extravagance of Harun al Rashid's court.

Ja'far ibn Yahya, who had inherited the position of vizier to the caliph from his father, Yahya, has a reputation as a patron of the sciences, and has done much to introduce Greek science into Baghdad, attracting scholars from the nearby Academy of Gundishapur to help translate Persian works into Arabic (the so-called "Translation Movement").

He is also credited with persuading the caliph to open a paper mill in Baghdad, the secret of papermaking having been obtained in 751 from Chinese prisoners at the Battle of Talas in present day Kyrgyzstan.

Moreover, Ja'far has become Harun's special friend, so that gossip speaks of a homosexual relationship.

Gossip also alleges that Harun had arranged that Ja'far should secretly marry his sister 'Abbasah, on condition that he did not consummate the marriage, but Ja'far fell in love with her, and she had a child.

Whether in anger at this or not, Harun has the thirty-six-year-old Ja'far executed on January 29, 803, and parts of his body displayed on the bridges of Baghdad.

The other members of the family are imprisoned and their goods confiscated.

Diverse interests within the 'Abbasid empire are being attracted to two opposing poles.

On the one side are the “secretaries’”, or civil servants, many Persians, and many men from the eastern provinces; on the other side are the religious scholars ('ulama'), many Arabs, and many from the western provinces.

Since the Barmakids favor the first group of interests and the new vizier, al-Fadl ibn ar-Rabi', favors the second, it is likely that this political cleavage is involved in the change of ministry.