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 an estimated total value of between US$250 and US$300 million annually (100 times more than the official figure). This trade helps lower food prices, increase food security, relieve border tensions and promote regional integration. However, there are also risks as the unregulated and undocumented nature of this trade runs risks, such as allow disease to spread more easily across national borders. Furthermore, governments are unhappy with lost tax revenue and foreign exchange revenues. Much of the Horn nations' trade links are with Middle Eastern countries. In 2011, an event hosted by the Arab Center for Research and Policy Studies in