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 species total and about 90 species which are found exclusively in the region. Among endemic reptile genera, there are "Haackgreerius", "Haemodracon", "Ditypophis", "Pachycalamus" and "Aeluroglena". Half of these genera are uniquely found on Socotra. Unlike reptiles, amphibians are poorly represented in the region. There are about 100 species of freshwater fish in the Horn of Africa, about 10 of which are endemic. Among the endemic, the cave-dwelling Somali blind barb and the Somali cavefish can be found. It is estimated that about 5,000 species of vascular plants are found in the Horn, about half of which are endemic. Endemism is