When the city of Cairo was rebuilt and laid out by the Fatimids in 969–974 (358 Hijri), and named al-Quahira (“the Victorious”), 20 percent of it—roughly 30 hectares—was devoted to open space. East of the al-Mu’izz palace, horseriding grounds were turned into a royal park and garden and a large central space to the west was dedicated to military parades and religious gatherings. A dozen years later, the al-Azhar (“the Radiant”) mosque and theological college were built (989). During the Fatimid, Ayyubid, and Mamluke periods, Cairo was one of the most advanced cities of learning in the Islamic world, evident today in its many magnificent landmark buildings. By the mid-twentieth century, however, population pressures and high-rise construction built to meet the consequent demand had made it one of the largest and most complex cities in the world. Today greater Cairo is home to some 17 million people. Compounding this growth has been an urban dynamic characterized by disinvestment in the city center areas—particularly in the maintenance and development of housing—and an influx of people, which has created stresses in the urban fabric that have relegated many people to lower standards of living.