The Savirs, historical ancestors of the Chuvash, spent more than seven centuries in the Caucasus. In the mid-2nd century they were recorded there by Ptolemy, while in the 860s they were moving up the River Itil (Volga) after living in the North Caucasus-Don area. In the Hun era they fought now on the side of the Persians, now with the Byzantines. After the loss of Hunnish unity, the Savirs became the most powerful social entity in the region. On the basis of the sources, the author considers that the Savirs were very numerous: there may have been up to a million of them, counting warriors and their households.