The Azerbaijani people are of mixed ethnic origins. These include the indigenous peoples of eastern Transcaucasia, the Medians, an ancient Iranian people, and the Oghuz Turkic tribes that began migrating to Azerbaijan in the 11th century AD. Modern Azerbaijanis are the second most numerous ethnic group among the Turkic peoples after Anatolian Turks and speak North Azerbaijani (spoken mainly in the Republic of Azerbaijan and Russia) and/or South Azerbaijani (spoken in Iran, Iraq and Syria). Both languages also have dialects, with 21 North Azerbaijani dialects and 11 South Azerbaijani dialects.