Cameroon is part of the original home of the Bantu cultural grouping who migrated east and south into the countries now known as the Central African Republic, Gabon and Congo. Little was known about the territory until the arrival of the Portuguese in 1472. Explorer Fernando Po named the Wuri River Rio dos Camarôes (shrimp or prawn) after large crustaceans found at its mouth. This evolved into the country's present name, Cameroon. During the following three centuries several other European nations and American traders operated along the Cameroon coast. In 1884, it became the German protectorate of Kamerun, but after the First World War the League of Nations allocated 80% of the territory to France (French Cameroun) and the remaining 20%, consisting of two separate areas along the Nigerian border, to the British as Northern and Southern Cameroons. After a protracted insurgency led by the Bamileke, French Cameroun gained its independence in 1960 under President Ahmadou Ahidjo who adopted single-party rule. Parts of the British Cameroons opted to join newly-independent Cameroon while others voted to merge with Nigeria. In 1982 Ahidjo resigned on grounds of ill health and handed power over to Prime Minister Paul Biya. A war of words between the two former allies led to a trial and a death sentence in absentia for Ahidjo, found guilty of subversion. In March 1992 Biya won reelection in disputed multiparty elections. He was reelected in 1997 and in 2004.