TOP SECRET GUARD NIGERIA 10. The coastal area of Nigeria has had long, if intermittent, contact with Western Europe. The Northern part, ruled by powerful Fulani Emirs and largely Muslim in belief, remained for long relatively isolated, but by the early twentieth century the whole of what is now the Colony and Protectorate of Nigeria came effectively under British administration. The Mandated, now Trusteeship, territory of the Cameroons, under United Kingdom administration, was added after the 1914-18 war.