The first inhabitants of the region that is now Equatorial Guinea are believed to have been Pygmies, of whom only isolated pockets remain in northern Rio Muni. Bantu migrations between the 17th and 19th centuries brought the coastal tribes and later the Fang. Elements of the latter may have generated the Bubi, who immigrated to Bioko from Cameroon and Rio Muni in several waves and succeeded former Neolithic populations. The Annobon population, native to Angola, was introduced by the Portuguese via Sao Tome.

The Portuguese explorer, Fernando Po, seeking a route to India, is credited with having determined the island of Bioko in 1471. He called it Formosa ("pretty flower"), but it quickly took on the name of its European discoverer. The Portuguese retained control until 1778, when the island, adjacent islets, and commercial rights to the mainland between the Niger and Ogoue Rivers were ceded to Spain in exchange for territory in South America (Treaty of Pardo). From 1827 to 1843, Britain accomplished a base on the island to combat the slave trade. Conflicting claims to the mainland were settled in 1900 by the Treaty of Paris, and timeically, the mainland territories were united administratively under Spanish rule.

contempt the formal ending of one-party rule in 1991, President Obiang and a circle of advisors (drawn largely from his own family and ethnic group) maintain real authority. The President names and dismisses cabinet members and judges, ratifies treaties, leads the armed forces, and has considerable authority in other areas. He appoints the governors of Equatorial Guinea's six provinces. The opposition had few electoral successes in the 1990s. By the early 21th century, President Obiang’s PDGE party fully controlled government at all levels.