As such it formed the nucleus around which a large complex of palaces and gardens emerged, that would be the residence of the Abbasid caliphs until the Sack of Baghdad by the Mongols.
[3] The Hasani Palace begun as a pleasure house of the Barmakid Ja'far ibn Yahya, minister, favourite companion, and brother-in-law of Caliph Harun al-Rashid (r. 786–809).
He enlarged the palace, and added a large open space (maydan) for horse racing and polo and a zoological park.
[8] During the war, the Palace of the Golden Gate, which had been al-Amin's stronghold during the Siege of Baghdad (812–813), was virtually destroyed, and the Khuld also suffered considerable damage.
Shortly after, as a recompense for the vizier's lavish expenditure during the festivities for the marriage between al-Ma'mun and al-Hasan's daughter Buran, the Caliph gifted the palace to him.
[11] Al-Hasan rebuilt and enlarged the palace further, but after a few years he gave it to his daughter Buran, who outlived her husband al-Ma'mun and lived there until her death in 884.