Horn of Africa covered the Simien and Bale Mountains but melted at the beginning of the Holocene. The mountains descend in a huge escarpment to the Red Sea and more steadily to the Indian Ocean. Socotra is a small island in the Indian Ocean off the coast of Somalia. Its size is 3,600 km (1,390 sq mi) and it is a territory of Yemen. The lowlands of the Horn are generally arid in spite of their proximity to the equator. This is because the winds of the tropical monsoons that give seasonal rains to the Sahel and the Sudan blow from the west.
Horn of Africa eventually transformed into Islamic Mogadishu, Berbera, Zeila, Barawa and Merka, which were part of the "Berber civilization". The city of Mogadishu came to be known as the "City of Islam" and controlled the East African gold trade for several centuries. During the Middle Ages, several powerful empires dominated the regional trade in the Horn, including the Adal Sultanate, the Ajuran Sultanate, the Warsangali Sultanate, the Zagwe dynasty, and the Sultanate of the Geledi. The Sultanate of Showa, established in 896, was one of the oldest local Islamic states. It was centered in the former Shewa province in central Ethiopia. The