in the late sixth century the territory of albania became again an arena of wars between sassanian persia and the byzantine/eastern roman empire. during the third perso-turkic war, the khazars (gokturks) invaded albania, and their leader ziebel declared himself "lord of albania" in 627 ad under the roman heraclius rule, levying a tax on merchants and the fishermen of the kura and araxes rivers, which was "in accordance with the land survey of the kingdom of persia". the albanian kings retained their rule by paying tribute to the regional powers.