by the Adalites. When the last Sultan of Ifat, Sa'ad ad-Din II, was also killed by Emperor Dawit I in Zeila in 1410, his children escaped to Yemen, before later returning in 1415. In the early 15th century, Adal's capital was moved further inland to the town of Dakkar, where Sabr ad-Din II, the eldest son of Sa'ad ad-Din II, established a new base after his return from Yemen. Adal's headquarters were again relocated the following century, this time to Harar. From this new capital, Adal organized an effective army led by Imam Ahmad ibn Ibrahim al-Ghazi (Ahmad "Gurey" or "Gran") that invaded the Abyssinian empire. This 16th century campaign is historically known as the Conquest of Abyssinia (Futuh al-Habash). During the war, Imam Ahmad pioneered the use of cannons and firearms supplied by the Ottoman Empire, which he imported through Zeila and thousands of mercenaries from the Muslim world and nomadic Somalia to wage a 'holy war' against Ethiopian King of Kings. The few Portuguese under Cristóvão da Gama that later that came to assist their Ethoipian coreligionist would tip the scale in their favour. Some scholars argue that this conflict proved, through their use on both sides, the value of firearms like the matchlock musket, cannons and the arquebus over traditional weapons. During the Age of the Ajuran, the sultanates and republics of Merca, Mogadishu, Barawa, Hobyo flourished and had a lucrative foreign commerce, with ships sailing to and coming from Arabia, India, Venetia, Persia, Egypt, Portugal and as far away as China. Vasco da Gama, who passed by Mogadishu in the 15th century, noted that it was a large city with houses several storeys high and large palaces in its center, in addition to many mosques with cylindrical minarets. The city of Mogadishu came to be known as the City of Islam, and controlled the East African gold trade for several centuries. In the 16th century, Duarte Barbosa noted that many ships from the Kingdom of Cambaya in modern-day India sailed to Mogadishu with cloth and spices, for which they in return received gold, wax and ivory. Barbosa also highlighted the abundance of meat, wheat, barley, horses, and fruit on the coastal markets, which generated enormous wealth for the merchants. Mogadishu was also the center of a thriving textile industry known as toob benadir, specialized for the markets in Egypt, among other places. Modern era Because Muslims