In the 7th century, Islam was introduced with the Arab conquest, which was important in the formation of a single nation and language in Azerbaijan, when the population became Muslim. A common religion for both Turkic and non-Turkic ethnic groups brought about the formation of common traditions, and the integration between the different ethnic groups living on the territory of Azerbaijan. By the middle of the 9th century, the Turkic ethnic group, the Azerbaijani people became the major ethnic group.