 Military architecture was the supreme expression of the Ayyubid period , as well as an eagerness to fortify the restoration of Sunni Islam , especially in a previously Shia @-@ dominated Egypt by constructing Sunni madrasas . The most radical change Saladin implemented in Egypt was the enclosure of Cairo and al @-@ Fustat within one city wall . Some of the techniques of fortification were learned from the Crusaders , such as curtain walls following the natural topography . Many were also inherited from the Fatimids like machicolations and round towers , while other techniques were developed simultaneously by the Ayyubids , particularly concentric planning . 
