At the Berlin Conference (1884-1885), the European powers were establishing the rules for setting up zones of influence or protection in Africa, and Spain declared 'a protectorate of the African coast' from Cape Blanc to Cape Bojador on 26 December 1884. It officially informed the other powers in writing on 14 January 1885. It began establishing trading posts and a military presence. In July 1885, King Alfonso XII appointed Emilio Bonelli commissioner of the Río de Oro with civil and military authority. On 6 April 1887, the area was incorporated into the Captaincy General of the Canary Islands for military purposes. In the summer of 1886, under the sponsorship of the Spanish Society of Commercial Geography (""), Julio Cervera Baviera, Felipe Rizzo (1823–1908) and Francisco Quiroga (1853–1894) traversed the territory, which was called Río de Oro, and made topographical and astronomical observations. At the time, geographers had not mapped the territory and its features were not widely known. Their trek is considered the first scientific expedition in that part of the Sahara.