It was standard in early Islamic architectural practice to build the Dar al-Imara or "palace of the governor" off the area adjacent to the main city mosque's qibla wall to afford the caliph direct access to the mosque. In Kufa, Iraq, the Dar al-Imara of Ziyad ibn Abihi, built in 670, was positioned south of the Great Mosque.
Constructed in baked brick, this building is the first example of an Islamic palace that architecturally draws on Sasanian fortresses. After several seasons of work, the Iraqi Department of Antiquities found three layers of construction. The first layer is either from the Islamic invasion of Iraq or earlier. The second dates from the Umayyad period, and the third to early Abbasid times.
The first layer reveals a 114 square meter foundation and a gateway on the north side, with the building supported by a total of 20 square towers, four of which are at the corners.
The second layer includes a palace encompassed by exterior and interior walls. The outer walls are four meters thick and measure approximately 170 square meters. Circular buttresses stand at each corner except the one to the northwest, which connects to the mosque. The interior wall is about 110 square meters. Like the first layer, this one too is supported by 20 towers with its main gate centrally located in the north side. Comparable to the palaces at Mshatta and Anjar in its organization, the Dar al-Imara is divided into thirds on a north-south axis with a central courtyard located in the northern half of the middle section. In addition, the rest of the palace at this layer includes an arrangement of bayts with various sized smaller courtyards, and a throne room that is preceded by a vaulted corridor.
The third layer found during excavation incorporates a large hall adjacent to a square courtyard and displays brickwork reminiscent of Damghan and Ukhaider. Architecturally, the Dar al-Imara is important for its characteristically Sassanian triple-aisled assembly room featuring a domed chamber at its rear.
Creswell, K. A. C.1989. A Short Account of Early Muslim Architecture. Rev. ed. Allan, James W. Aldershot: Scolar Press, 10-15.