Azerbaijanis (; , ) or Azeris (), also known as Azerbaijani Turks (, ), are a Turkic ethnic group, living mainly in the sovereign Republic of Azerbaijan and the Azerbaijan region of Iran, with a mixed cultural heritage, including Turkic, Caucasian and Iranian elements. They are the second-most numerous ethnic group among the Turkic-speaking peoples after Turkish people and are predominantly Shia Muslims. They comprise the largest ethnic group in the Republic of Azerbaijan and the second-largest ethnic group in neighboring Iran and Georgia. The world's largest number of ethnic Azerbaijanis live in Iran, followed by the Republic of Azerbaijan. They speak the Azerbaijani language, belonging to the Oghuz branch of the Turkic languages.