Horn of Africa Himyarite Kingdom. Under Ezana (fl. 320–360), the kingdom of Aksum became the first major empire to adopt Christianity, and was named by Mani as one of the four great powers of his time, along with Persia, Rome and China. Northern Somalia was an important link in the Horn, connecting the region's commerce with the rest of the ancient world. Somali sailors and merchants were the main suppliers of frankincense, myrrh and spices, all of which were valuable luxuries to the Ancient Egyptians, Phoenicians, Mycenaeans, Babylonians and Romans. The Romans consequently began to refer to the region as "Regio Aromatica". In
Horn of Africa the Adal Sultanate with Zeila as its headquarters dates back to at least the 9th or 10th century. According to I.M. Lewis, the polity was governed by local Somali dynasties, who also ruled over the similarly-established Sultanate of Mogadishu in the littoral Benadir region to the south. Adal's history from this founding period forth would be characterized by a succession of battles with neighbouring Abyssinia. Islam was introduced to the region early on from the Arabian peninsula, shortly after the hijra. At Muhammad's urging, a band of persecuted Muslims had fled across the Red Sea into the Horn. There, the