In 1171, the Damascus-appointed governor, Salah el-Din (Saladin) overthrew the last Fatimids caliph and seized power himself, establishing the Abbasid Dynasty.

Salah El-Din (Saladin) built the Citadel in 1183 A. D. as the centre of government, while simultaneously extending and restoring the city fortifications, with the aim to dominate Cairo from Mokattam Hills. This huge project was incomplete at his death, and much work continued in later times.

Cairo is the best preserved of all Islamic cities, and substantial parts of Salah el-Din's structures remain today. In spite of the impounding of the defensive towers, the Cairo Citadel is, from a military point of view, slightly less substantial than the Citadel of Aleppo (In Syria), but it remains one of the most notable existing examples of Muslim military architecture. The skilful masonry work and the impressive vaulting in particular have no precedent in Egypt.

After the death of Salah al-Din, his nephew, Al-Kamel, reinforced the Citadel by enlarging several of the towers. Specifically, he encased the Blacksmith's Tower & the Sand Tower making them fully three times larger. These two towers controlled the narrow pass between the Citadel and the Mokattam Hills. Al-Kamel also built a number of great keeps (towers) around the perimeter of the walls.

These massive structures were square, up to 25 meters (80 ft) tall and 30 meters (100 ft) wide. In 1218, upon the death of al-Kamel's father, Sultan al-Kamel moved his residence to the Citadel where he built his palace in what is now the Southern Enclosure. While the palace no longer exits, until the construction of the Abdien Palace in the mid-19th century, it was the seat of government for the Country of Egypt. The Citadel consists of three main sections, surrounded by their own walls with towers and gates. These consist of the Lower Enclosure, the Northern Enclosure and the Southern Enclosure which is the Citadel proper (El-Qal'a3). The two main gates are on the north (Bab el-Gadid) and south (Bab el-Gabal). Particularly when viewed from the back side (from the north), the Citadel reveals a very medieval character.