The region probably formed part of the “Land of Punt” known to the ancient Egyptians. Between the 7th and the 12th century CE, cities such as Seylac and Berbera on the Gulf of Aden served as trading ports in a region that the Arab Islamic world called bilad al-Barbar (“country of the Barbar”), Barbar (also Berber, Barbaroi) being a name for the Somali people of the region based on the descriptions of the inhabitants of the area found in the Greek document Periplus Maris Erythraei (1st century CE; “Navigation of the Erythrean [i.e., Red Sea]”). Those medieval cities exported gums and resins, ostrich feathers, and slaves and waged war against the Christian Ethiopians of the interior. The Somali, who occupied those areas alongside other groups, had begun adopting Islam in the 7th century, and the religion became firmly entrenched in the centuries that followed. The occupants of the cities organised themselves into sultanates such as Adal, centred at Seylac. When the European nations began to partition Africa among themselves in the late 19th century, other areas of the north coast were occupied by Egypt, Britain had established a protectorate over the north coast opposite its base at Aden. In Somaliland, the Muslim leader Sayyid Maxamed Cabdulle Xasan began a war against the British in 1899 and maintained his hold over the interior until his death in 1920.