A Sio youth, abducted by German officials and introduced to the governor of the colony, played a key role in establishing peaceful relations between the Sio and Whites during the German colonial period (1884-1914). A Lutheran mission station was established at Sio in 1910, and the same youth, now grown and an appointed village headman, helped lead the people toward mass conversion to Christianity in 1919. Since then a succession of leaders have conducted Sio's relations with outside agencies, drawing to the community varied benefits while insisting that land and resources remain under local control. In 1959, a government primary school opened and a regional service cooperative for marketing the copra and coffee of village producers was inaugurated. Both the school and the co-op owed much to Sio initiative. In the mid-1960s, Sio was incorporated in a local government council. Developments of the 1980s included cattle ranching, the formation of a Sio company engaged in logging of hardwoods in conjunction with an Asian firm, and, to compensate for the decline of the copra market—copra having been the principal cash crop—the extensive planting of cocoa.