Query: The trade of what luxury in East Africa was once centered on Mogadishu?
Context: With the migration of fleeing Muslim families from the Islamic world to Somalia in the early centuries of Islam and the peaceful conversion of the Somali population by Somali Muslim scholars in the following centuries, the ancient city-states eventually transformed into Islamic Mogadishu, Berbera, Zeila, Barawa and Merca, which were part of the Berberi civilization. The city of Mogadishu came to be known as the City of Islam, and controlled the East African gold trade for several centuries.