Doukas's Insight: Circassians and Abkhazians in Timur's Conquest
Doukas (c. 1400 – after 1462), a Byzantine historian who flourished under Constantine XI Palaiologos, the last Byzantine Emperor, reported in his work "History of Byzantium" that before the Battle of Ankara in 1402, the famous medieval commander Timur (Tamerlane) journeyed from Persia to the regions of the Don. There, he gathered the Scythians along with the Zykhians (Circassians) and Abasgians (Abkhazians).
Doukas writes ("Doukas, The Decline and Fall of Byzantium to the Ottoman Turks," translated by Harry J. Magoulias, Wayne State University Press, 1975, p.90):