The Turkic ancestors of the Chuvash people are believed to have come from central Siberia, where they lived in the Irtysh basin (between Tian Shan and Altay) from at least the end of the third millennium BC. In the beginning of the first century AD, the Bulgars started moving west through Zhetysu and the steppes of modern-day Kazakhstan, reaching the North Caucasus in 2nd–3rd centuries AD. There they established several states (Old Bulgaria on the Black Sea coast and the Suar Duchy in modern-day Dagestan.