leadership of Vizier Shawar set fire to Fustat to prevent Cairo's capture by the Crusaders. Egypt's capital was permanently moved to Cairo, which was eventually expanded to include the ruins of Fustat and the previous capitals of al-Askar and al-Qatta'i. While the Fustat fire successfully protected the city of Cairo, a continuing power struggle between Shawar, King Amalric I of Jerusalem, and Zengid general Shirkuh led to the downfall of the Fatimid establishment.
In 1169 Saladin was appointed as the new vizier of Egypt by the Fatimids and two years later he would seize power from the family of the last Fatimid caliph, al-'Āḍid. As the first Sultan of Egypt, Saladin established the Ayyubid dynasty, based in Cairo, and aligned Egypt with the Abbasids, who were based in Baghdad. During his reign, Saladin also constructed the Cairo Citadel, which served as the seat of the Egyptian government until the mid-19th century.
In 1250 slave soldiers, known as the Mamluks, seized control of Egypt and like many of their predecessors established Cairo as the capital of their new dynasty. Continuing a practice started by the Ayyubids, much of the land occupied by former Fatimid palaces was sold and replaced by newer buildings. Construction projects initiated by the Mamluks pushed the city outward while also bringing new infrastructure to the centre of the city. Meanwhile, Cairo flourished as a centre of Islamic scholarship and a crossroads on the spice trade route among the civilizations in Afro-Eurasia. By 1340, Cairo had a population of close to half a million, making it the largest city west of China.
Ottoman rule
Although Cairo avoided Europe's stagnation during the Late Middle Ages, it could not escape the Black Death, which struck the city more than fifty times between 1348 and 1517. During its initial, and most deadly waves, approximately 200,000 people were killed by the plague, and, by the 15th century, Cairo's population had been
