Urbanization during the colonial period was marked by forms of racial and social segregation—often expressed in terms of health and hygiene—which continue to structure the city today. Following a plague epidemic in 1914, the authorities forced most of the African population out of old neighborhoods, or "Plateau", and into a new quarter, called Médina, separated from it by a "sanitary cordon". As first occupants of the land, the Lebou inhabitants of the city successfully resisted this expropriation. They were supported by Blaise Diagne, the first African to be elected Deputy to the National Assembly. Nonetheless, the Plateau thereafter became an administrative, commercial, and residential district increasingly reserved for Europeans and served as model for similar exclusionary administrative enclaves in French Africa's other colonial capitals (Bamako, Conakry, Abidjan, Brazzaville). Meanwhile, the Layene Sufi order, established by Seydina Mouhammadou Limamou Laye, was thriving among the Lebou in Yoff and in a new village called Cambérène. Since independence, urbanization has sprawled eastward past Pikine, a commuter suburb whose population (2001 est. 1,200,000) is greater than that of Dakar proper, to Rufisque, creating a conurbation of almost 3 million (over a quarter of the national population).