Medieval Cairo, also known as Fatimid Cairo, was founded in 969 as the royal enclosure for the Fatimid caliphs, while the actual economic and administrative capital was in nearby Fustat. After Fustat was destroyed in 1168/9 to prevent its capture by the Crusaders, the administrative capital of Egypt moved to Cairo, where it has remained ever since. Muizz Street goes through Islamic Cairo and has great concentration of bazaars and Islamic architectures. After Memphis, Heliopolis, Giza and the Byzantine fortress of Babylon-in-Egypt, Fustat was a new city built as a military garrison for Arab troops.