a republic in S central Africa, with a narrow strip of land along the Congo estuary leading to the Atlantic in the west: Congo Free State established in 1885, with Leopold II of Belgium as absolute monarch; became the Belgian Congo colony in 1908; gained independence in 1960, followed by civil war and the secession of Katanga (until 1963); President Mobutu Sese Seko seized power in 1965; declared a one-party state in 1978, and was overthrown by rebels in 1997. The country consists chiefly of the Congo basin, with large areas of dense tropical forest and marshes, and the Mitumba highlands reaching over 5000 m (16 000 ft) in the east. Official language: French. Religion: Christian majority, animist minority. Currency: Congolese franc. Capital: Kinshasa. Pop: 81 339 988 (2017 est). Area: 2 344 116 sq km (905 063 sq miles)