The Songhai Empire (also transliterated as Songhay) was a state that dominated the western Sahel in the 15th and 16th century. At its peak the empire was one of the largest in African history. The empire bore the same name as its leading ethnic group, the Songhai people, the ruling elite in the empire. Sonni Ali established Gao as the capital of the empire, although a Songhai state had existed in and around Gao since the 11th century. Other important cities in the empire were Timbuktu and Djenné, conquered in 1468 and 1475 respectively, where urban-centered trade flourished. Initially, the empire was ruled by the Sonni dynasty (–1493), but it was later replaced by the Askiya dynasty (1493–1591).