There have been a number of historical African states of varying size and influence: * Iron Age empires of North Africa * Ancient Somali city states on the Berber coast. * Medieval (8th to 13th century) Islamic empires (caliphates) in North Africa and the Horn of Africa * Medieval and modern Somali states. * The medieval Sahelian kingdoms * The Ethiopian Empire is notable as an empire in continuous existence from the 13th to the 20th centuries. * Empires of the 15th to 19th centuries. * Islamic sultanates of the Sudan and the Horn of Africa * Kingdoms of West Africa succeeding the Sahelian kingdoms * Kingdoms of Central and Southern Africa such as the Kongo Kingdom and the Mutapa Empire.