The Kuma, the Terek and the Kura, with the Aras, which receives the waters of Lake Gok-cha, belong to Caucasia.'
The southern boundary of Caucasia is in part coincident with the river Aras (Araxes), in part purely conventional and political.
This line of heights separates the basins of the Chorokh and the Rion (Black Sea) from those of the Aras and the Kura (Caspian Sea).
The Erivan line is being continued into Persia, namely, to Tabriz via Julfa on the Aras.
The southern boundary never greatly altered; it did at times reach the Kur and the Aras, but on that side the Khazars were confronted by Byzantium and Persia, and were for the most part restrained within the passes of the Caucasus by the fortifications of Dariel.
