The founder :
Ahmed Ibn Tulun ( 263-265 A.H ), born about 835 A.D, he is one of the Turkish commanders in Samarra in Iraqu. He receives his military and theological training in Samarra and Tarsus .His intelligence and courage attracted the attention of the Khalif and in 868 A.D he made proxy for his step-father Bakabak's governorship of Egypt.
He established himself as an independent ruler for the Province. An abortive attempt to remove him encouraged Ahmed to attach Syria.
Ahmed Ibn Tulun founded a new Capital called Alqatai around the hill of Gabal Yashkur, to the NE of Al Fustat, razing the Christian and the Jewish cemetery that was located in that area.
The Mosque
The site chosen for his mosque was an outcrop of rock called Gabal Yashkur. Is It situated in sharia Al Saliba.
1-It is the oldest intact functioning Islamic monument in Cairo. It is considered the 3rd mosque which was constructed for the whole community or the congregation joined together for the Friday noon prayer.
2- It is also rare preserved example of the art and the architecture of the classical period of Islam.
It is one of the biggest mosques in Egypt. The mosque together with the ziyada occupies an area of 6.5 acres.
The plan of the Mosque:
It is nearly square in shape, measures 162 m. in length and 161 m. in width. The area which is dedicated for the prayer is rectangular in shape measures about 137 m. x 118 m.
It was designed as open court or central square Sahn (about 92 m) Surrounded by four riwaqs. The riwaq of the quibla contains 5 arcades . while each of the other riwaqs consists of 2 arcades.
The mosque surrounded by Ziyadas ( extension) on 3 sides, the Ziyada is an enclosed space or precinct to separate the mosque from the markets and in order to protect the mosque and the prayers from the noise of the street.
Outside the mosque on the quibla wall there was a palace or Dar El Imarah (house of the government, or the ruler residence ), now destroyed, with its own entrance near to the Mihrab from which Ahmed Ibn Tulun used to enter to the mosque before leading the prayer.
The Entrance of the Mosque:
This mosque has19 doors on 3 sides, each door corresponding To another door in the ziyadas, and there are another 3 doors cut in the wall of the quibla. The lintels are composed of palm-trunks, boxed with wood and above a releasing arch, some of these doors still retain their original carving.
The Foundation Slate:
On the right hand central Pier of the 3rd arcade from the sahn is the Foundation Slate ; it includes the Foundation Inscription, it is a rectangular slab of marble ( 1,6 m X 97 cm) written in Kufic inscription and it contains The verse of El Kursi ( Ayat Al Kursi) from the Koran and the date of 265 A.H
The Crenulations:
Both the walls of the mosque and the Ziyada are crowned with crenulations which are similar to the paper cut-outs of human figures with linked arms.
The Sahn ( the courtyard ):
It is square in shape, each of its sides measures about 92 m.
The original courtyard was not paved and filled with pebbles as it is today, because this space was intended for prayer.
The Fawarah in the middle of the Sahn is the 3rd one, the first one was the original built by Ahmed Ibn Tulun. It was gilded and stood on 10 columns of marble. The 2nd one was Al Aziz but was destroyed .The actual one is the third built by The sultan Lagin Al Mansoury among some other works he did for the mosque. ( 14 X 12 m ) and it is 20 m in height. This Fawarah was built by the architect Ibn Al Roumyyah. It has a Mameluk design; it is stood on 4 pointed arches , the zone of transition has stepped corners with a window in the uppermost step and 3 windows of 3 lights on each side. The dome is plain without a drum and raised on squinch. Above, a continuos stalactite frieze runs around the base of the dome and above that a band of Naskhi inscription from the Koran dealing with the ablution.
The Arcades:
The arcades around the courtyard or the Sahn which are deeper on the quibla Riwaq or the sanctuary side are formed by pointed Arches on brick Piers .Rosettes and windows form a continuous and simple decoration. These arcades are supported by piers.
Unlike columns.These Piers are rectangular and decorated with four masonry-engaged columns. Their capitals have the same bell shape as the bases, and both plastered and carved. Originally would seem that all of the arcades had soffits of curved stucco similar to those which have been restored in the Southern arcade.
The arches:
The Arches of the arcades are pointed, They are outlined with an edge of carved stucco, and spring from oblong supports rounded at the corners by pilasters or engaged columns.
The Quibla Riwaq ( The Sanctuary ):
It includes 5 aisles deeper than the others and they are parallel to the Prayer niche ( the Mihrab), while each of the other riwaq includes just 2 aisles . This Riwaq actually has 6 prayer niches or mihrabs
The main Mihrab is in the middle of the quibla wall, it is the tallest and the only concave one The others are flat .It consists of a double pointed arched recess flanked by a pair
Byzantine style marble columns with basket work capitals. Its stucco moluding and the 2 stucco bosses on each side of the arch are original. The interior is decorated in Mameluk style made by the sultan Lajin, the upper decoration of painted wood, and strips of polychrome marble , above which is a band of Naskhi inscription in black mosaic on a gold background containing the shahada. The Dikka of the Mouballegh ( the bench of the Mouballegh) is situated in Riwaq. Al Quibla near the courtyard. It is a wide bench of marble columns used for communicating the words of the Imam during the prayer.
The Ceiling:
The ceiling is composed of Palm logs boxed in wooden panels. Below the ceiling there are a long band of inscription on sycamore wood which runs around the whole mosque contains verses from the Koran. This frieze is 2 Km. In length, and it is calculate one fifteenth of the whole holly book .There is a legend that the boards used for this inscription are left over from the Noah's Ark.
The Windows:
The upper part of the mosque wall is pierced with pointed arch windows flanked with colonnades .The windows alternate on the outside wall within blind niches with a shell conch .
There are 128 windows and their arrangements on the walls are independent of the arches so that not every arch has a centred window. The functions of these arched windows of the arched windows are providing light and reduce the weight carried by the arches.
Creswell attributes only 4 of the windows stucco grills to the Tulunide Period, those of the plain geometrical design, while the rest displaying a large variety of more complicated geometrical patterns date back to the Fatimide and the Mameluk Periods.
The Minaret:
It stands on the North side of the Ziyada, where a door leads to it is an unusual stone structure with an outer staircase, and a Mameluk top of the type named Mabkhara. This minaret caused controversy among the Cairo's Architectural historians. We don't have enough sources to clear this point or determine its date.