The earliest state in Eritrea and northern Ethiopia, Dʿmt, dates from around the 8th and 7th centuries BC. D'mt traded through the Red Sea with Egypt and the Mediterranean, providing frankincense. By the 5th and 3rd centuries, D'mt had declined, and several successor states took its place. Later there was greater trade with South Arabia, mainly with the port of Saba. Adulis became an important commercial center in the Ethiopian Highlands. The interaction of the peoples in the two regions, the southern Arabia Sabaeans and the northern Ethiopians, resulted in the Ge'ez culture and language and eventual development of the Ge'ez script. Trade links increased and expanded from the Red Sea to the Mediterranean, with Egypt, Israel, Phoenicia, Greece, and Rome, to the Black Sea, and to Persia, India, and China. Aksum was known throughout those lands. By the 5th century BC, the region was very prosperous, exporting ivory, hippopotamus hides, gold dust, spices, and live elephants. It imported silver, gold, olive oil, and wine. Aksum manufactured glass crystal, brass, and copper for export. A powerful Aksum emerged, unifying parts of eastern Sudan, northern Ethiopia (Tigre), and Eritrea. Its kings built stone palatial buildings and were buried under megalithic monuments. By 300 AD, Aksum was minting its own coins in silver and gold.