Under the Ottomans, Cairo expanded south and west from its nucleus around the Citadel. The city was the second-largest in the empire, behind Constantinople, and, although migration was not the primary source of Cairo's growth, twenty percent of its population at the end of the 18th century consisted of religious minorities and foreigners from around the Mediterranean. Still, when Napoleon arrived in Cairo in 1798, the city's population was less than 300,000, forty percent lower than it was at the height of Mamluk—and Cairene—influence in the mid-14th century.