The islands of Africa are a major geographical sub-region of Africa, and represent a distinct demographic and historical cultural sphere of influence on the continent. Introduction The islands of Africa can be subdivided into Indian Ocean Islands and Atlantic Ocean Islands. The largest number of islands of Africa are found in the Indian Ocean, with the sovereign island nations of Comoros, Seychelles, Mauritius and Madagascar located off the southeastern seaboard of Africa being the most notable. The French overseas territories of Mayotte and Réunion are also located nearby. The medium-sized islands of Zanzibar and Lamu of Tanzania and Kenya, respectively, are also located in the Indian Ocean, in addition to smaller islands off the coasts of other continental countries. In the Atlantic seaboard, the largest islands are Cape Verde off the coast of West Africa and Sao Tome and Principe off the southwestern seaboard. In the Atlantic Ocean, the island of Bioko and other smaller islands of Equatorial Guinea are also notable. The Canary Islands and other territories of Spain are present in the Mediterranean Sea in the north Atlantic Ocean, and the British possessions of Saint Helena, Ascension Island, and Tristan da Cunha are located off the southwestern seaboard of the continent. Geology All of the islands of Africa, except for Madagascar, are classified as small islands under the UNESCO classification system for all islands under . Madagascar, in contrast, at is the fourth-largest island in the world. In line with most characteristics of small islands, the islands of Africa with the exception of Madagascar are almost all volcanic in origin, high in structure, with low coral elevation, with some surface water resources and undergo variable weather conditions, with occasional destructive tropical cyclones. Geography and history Sovereign island nations Indian Ocean islands There are four sovereign island nations located in the Indian Ocean: Comoros, Madagascar, Mauritius and Seychelles. These countries have interrelated histories and populations over hundreds of years of interaction. These islands, in addition to the French territories of Réunion and Mayotte make up the membership of the Indian Ocean Commission. Each of the sovereign Indian Ocean nations have complex population histories with Southeast Asian exploration and settlement, Arab trade and the Bantu migrations each playing a crucial role before later European colonization. The Malagasy settled the largest island of the Indian Ocean (and the fourth-largest globally), Madagascar, along with a group of smaller islands nearby, namely Réunion