Constantine Porphyrogenitus wrote in his work On Administering the Empire that the Khagan and the Bek of the Khazars asked the Emperor Teophilos to have the fortress of Sarkel built for them.
Khagan | Bek | Antony Bek | Antony Bek (bishop of Durham) | Yunus-Bek Yevkurov | Ulrich von Bek | Khagan Bek | khagan | Khachatur-Bek of Mush |