The first system of public education in Mauritania was established by the French colonial administration. The first schools were largely concentrated in the sedentary communities of the Sénégal River Valley. In 1950, the first teacher training school was established at Boutilimit, and in 1957, the secondary school in Rosso also began training teachers. In part because public schools were concentrated in the south, black Africans enrolled in large numbers. As a result, the overwhelming majority of public school teachers were black, and the nation's secular educated class was dominated by black people.