While the social history of Dakar, Senegal, exhibits many of the characteristics common to most Eurafrican cities on the West coast, the rather abrupt manner in which the policy of residential segregation replaced the earlier pattern of co-existence, if not integration, of the African and European populations merits particular attention. The establishment of the Medina—the ‘native quarter’, to employ the colonial idiom of the day—was the most decisive and significant action taken by the French authorities in the history of the city. Yet this decision resulted from no carefully considered change in administrative policy, which had been somewhat laissez-faire in residential matters, but rather was hastily urged after the outbreak of a severe epidemic of bubonic plague in 1914. What began medically was to become, however, a major social and urban problem.