Cameroon is a country in west-central Africa, formally known as the Republic of Cameroon. Nigeria is on the west and north; Chad is on the northeast; the Central African Republic is on the east; and Equatorial Guinea, Gabon, and the Republic of Congo are on the south. The Bight of Biafra, which is part of the Gulf of Guinea and the Atlantic Ocean, is its coastline. Due to its strategic location at the crossroads of West and Central Africa, the country is sometimes referred to as West African and other times as Central African. The Sao civilization around Lake Chad and the Baka hunter-gatherers in the southeastern rainforest were among the first inhabitants of the region, which speak 250 native languages. In the 15th century, Portuguese explorers arrived on the coast and called the region Rio dos Camares, which became Cameroon in English. In the nineteenth century, Fulani soldiers established the Adamawa Emirate in the north, and various ethnic groups in the west and northwest established influential chiefdoms and fondoms. In 1884, Cameroon was renamed Kamerun and became a German colony. As a result of League of Nations mandates, it was split between France and the United Kingdom after World War I. The Union des Populations du Cameroun (UPC) was a pro-independence political group that was banned by France in the 1950s, resulting in the Bamileke War, which lasted until early 1971 and was fought between French and UPC militant powers. President Ahmadou Ahidjo led the French-administered portion of Cameroon to independence in 1960 as the Republic of Cameroun. In 1961, it federated with the southern part of British Cameroons to create the Federal Republic of Cameroon. In 1972, the federation was disbanded. In 1972, the nation was renamed the United Republic of Cameroon, and in 1984, it was renamed the Republic of Cameroon. The current president, Paul Biya, has been in office since 1982; he previously served as Prime Minister from 1975 to 1982. Cameroon is governed by a presidential unitary republic. Cameroon's official languages are French and English, which are both the official languages of former French and British Cameroons. Its religious community is mostly Christian, with a small minority of Muslims and others adhering to traditional religions. It has faced opposition from English-speaking regions, where lawmakers have called for further decentralisation, if not full secession or independence. Tensions over the establishment of an Ambazonian state in English-speaking territories reached a breaking point in 2017. Subsistence farming is practiced by a large number of Cameroonians. Because of its geographical, linguistic, and cultural diversity, the nation is sometimes referred to as "Africa in miniature." Beaches, deserts, mountains, rainforests, and savannas are among the country's natural features. Mount Cameroon in the Southwest Region is the highest point at almost 4,100 meters.