Republic of W central Africa, S of the Republic of Cameroon. It consists of the island s of Bioko (Fernand o Po), Annobon, Corisco, Elobey Grand e, and Elobey Chico in the Gulf of Guinea and the mainland province of Rio Muni. Malabo on Bioko is its capital. Annobon and Fernand o Po were ceded to Spain in 1778 by Portugal, but the region was aband oned in 1781 because of disease. The British used Malabo and San Carlos for their antislavery patrols from 1827 to 1843. The island s were gradually settled by Spain in the 19th century. Rio Muni was awarded to Spain in 1885 by the Congress of Berlin. Independence from Spain was achieved on October 12, 1968, with Macias Nguema as president, and in 1969 most Europeans were forced from Rio Muni by African demonstrations. In 1972, Nguema appointed himself president for life. Equatorial Guinea became a unitary state in 1973 following the adoption of a new constitution. The Nguema dictatorship was characterized by human rights violations, tension with neighboring states, and the deaths of thousand s of perceived opponents to the government. In 1979, a military coup executed Nguema and installed his nephew Lieutenant Colonel Teodoro Obiang Nguema Mbasogo as the new president. While there was improvement, Mbasogo was still in power more than 20 years later following a series of elections in the 1990s during which the opposition was suppressed or boycotted the elections.