It is 44 miles long from N.N.E. to S.S.W. and about 20 miles across.
The island was discovered in 1472 by the Portuguese navigator Fernão da Po.
Portugal ceded to Spain Fernando Poo, Annobon and the Guinea coast in 1778, with the Treaty of El Pardo.
Spain then mounted an expedition to Fernando Poo, led by the Conde de Argelejos.
From 1827 to 1843 the British leased bases at Port Clarence (modern Malabo) and San Carlos for the anti-slavery patrols.
Notably Fernando Poo was a central historical nexus in Robert Anton Wilson's Illuminatus! trilogy.