The Suku polity was founded by refugees from the middle Kwango River area, which was being conquered by Lunda invaders in the seventeenth century. Although the Suku are culturally akin to the Kongo peoples, their political organization and nomenclature carry a distinct Lunda imprint. After shallow and sporadic contacts with the Portuguese in the nineteenth century, in the 1890s the Suku came under the control of the Congo Free State (eventually the Belgian Congo). European traders appeared early in the twentieth century; serious missionary (Catholic and Protestant) and government presence commenced in the late 1920s. From the 1930s, the Suku economy, lacking local resources, became progressively dependent on labor migration to plantations and urban centers.