The territory of present day Cameroon was first settled during the Neolithic period. Portuguese sailors reached the coast in 1472. Over the following few centuries, European interests regularised trade with the coastal peoples, and Christian missionaries pushed inland. In the early 19th century, Modibo Adama led Fulani soldiers on a jihad in the north against non-Muslim and partially Muslim peoples and established the Adamawa Emirate. Settled peoples who fled the Fulani caused a major redistribution of population.
The German Empire claimed the territory as the colony of Kamerun in 1884 and began a steady push inland. With the defeat of Germany in World War I, Kamerun became a League of Nations mandate territory and was split into French Cameroun and British Cameroons in 1919. The French carefully integrated the economy of Cameroun with that of France and improved the infrastructure with capital investments, skilled workers, and continued forced labour.
The British administered their territory from neighbouring Nigeria. Natives complained that this made them a neglected "colony of a colony". The League of Nations mandates were converted into United Nations Trusteeships in 1946, and the question of independence became a pressing issue in French Cameroun. France outlawed the most radical political party, the Union des Populations du Cameroun UPC, on 13 July 1955. This prompted a long guerrilla war. In British Cameroons, the question was whether to reunify with French Cameroun or join Nigeria.
On 1 January 1960, French Cameroun gained independence from France under President Ahmadou Ahidjo, and on 1 October 1961, the formerly British Northern Cameroons became a part of Nigeria, while the formerly British Southern Cameroons united with its neighbour to form the Federal Republic of Cameroon.