Réunion was first settled in the 17th century by colonists from France. Slave labourers were brought in from East Africa to work on plantations, and later Malays, Annamites, Chinese, and Malabar Indians were imported as indentured labourers. Today most of the population is of mixed descent (Creole), with African descent predominant. The limited amount of land has induced substantial emigration, largely to France but also to Madagascar. The island's population density is high, even in areas that typically would be considered too mountainous to support a dense population. Saint-Denis, the capital and largest urban area on the island, contains almost one-fifth of the total population. The language in common use on the island is Creole; French, is the official language. About 90 % of the population is Roman Catholic.