The Mosque of Al Salih Tala’i (Arabic: مسجد الصالح طلائع) built by the Fatimid vizier al-Salih Tala’i’ ibn Ruzzik in 1160/554-555 AH during the caliphate of al-Fa’iz, is the second extant Fatimid mosque to be built by a vizier, the first being that of al-Aqmar. It is also the second of the hanging or “suspended” mosques (after al-Aqmar’s). The Mosque is situated in Bab Zuwayla Square, in the Darb al-Ahmar district facing Bab Zuwayla, one of the gates of the Fatimid City of Cairo’s southern wall, i.e. the mosque was built outside the city walls of Cairo, Egypt. Tala’i was one of the last powerful and capable viziers in the Fatimid Empire that retained a degree of stability in its last decades. As the Fatimid Caliphate collapsed in 1171, this mosque is the last (and still surviving) major Fatimid monument to have been completed. Originally it absolutely was conceived as a shrine to deal with the pinnacle of al-Husayn, which was dropped at Cairo from its shrine in Ascalon by the vizier when it had been threatened by an impending attack from the Crusaders. But the caliph instead kept the relic in an exceedingly shrine within the Fatimid palace, which became a part of the Mosque of al-Husayn when the palace was destroyed. The Al-Salih Tala’i Mosque is considered the last mosque to be built in Egypt during the Fatimid period. It comprises distinctive architectural features that are rarely found in any other mosque in Fatimid.
The intended use of the mosque as a shrine for a Shi’i martyr may account for the introduction of an entrance portico composed of five keel arches, a unique feature among Cairene mosques. The prayer hall consists of three aisles running parallel to the qibla wall; one aisle each has on the three other sides of the courtyard. The entrance to the mosque is fronted by a portico with five arches, a feature which was unique in Cairo (at least before the much later Ottoman period) and might need been intended for a few ceremonial purposes if the top of Husayn had been buried here as intended. A minaret originally also stood above the mosque’s entrance; the visible stairwell that still leads to the roof today possibly marks its former location. The exterior walls are made of stone; the interior arcades are formed by arches of brick keels carried on columns with the capitals of spolia. The arches are framed by a continual band of Qur’anic verses executed in a very floriated Kufic script (Kufic script on an arabesque background). The arches display wooden tie beams, which still show their original carving. Similar carving may also be seen on the wooden tabliyyas or impost blocks between the arches and also the column capitals. The house, measuring 53.50 m x 27 m, is rectangular in shape. There is an open courtyard at the middle of the mosque, and underneath the courtyard is a water cistern. Four roofed areas surround the courtyard, with rows of columns forming colonnades.
Today, the doors are replaced by replicas, while the originals are on display at the Museum of Islamic Art in Cairo, displaying both the Mamluk bronze-faced and Fatimid wood-carved facades. The exterior of the original door is faced with bronze plaques geometrically carved, which date back to 1303 when the mosque was rebuilt after an earthquake. Some of the historical sources indicate that al-Salih Tala’i built this mosque to bury within it the top of Husayn, the grandson of the Prophet Muhammad. However, the Fatimid caliph, al-Fa’iz bi Nasr Allah, refused to entertain the concept and insisted that it shouldn’t be placed anywhere except within the Palaces of Zahira, thus, he built the tomb within the good Fatimid Palace. Today, the mosque’s base (along with the shops that once lined its exterior) is almost two meters below the current level of the street, illustrating how much the level of the street in the city has risen since the 12th century. This is the second earliest existing example of a “suspended mosque” after al-Aqmar because it’s built above shops that make up part of the waqf.