Vahan at first endeavored to check the movement, being doubtful of the power of Armenia to cope with Persia, and feeling sure that the aid of the Greek emperor could not be counted on.

But the the popular enthusiasm overleaped all resistance; everywhere the Christian party rushed to arms, and swore to free itself; the Persians with their adherents fled the country; Artaxata, the capital, was besieged and taken; the Christians were completely victorious, and, having made themselves masters of all Persarmenia, proceeded to establish a national government, placing at their head as king, Sahag, the Bagratide, and appointing Vahan, the Mamigonian, to be Sparapet, or "Commander-in-Chief." Intelligence of these events recalled the Persian governor, Ader-Veshnasp, from Iberia.

Returning into his province at the head of an army of no great size, composed of Atropatenians, Medes, and Cadusians, he was encountered by Vasag, a brother of Vahan, on the river Araxes, with a small force, and was completely defeated and slain.
Thus ended the campaign of A.D.481.

In A.D.482 the Persians made a vigorous attempt to recover their lost ground by sending two armies, one under Ader-Nerseh against Armenia, and the other under Mihran into Iberia.

Vahan met the army of Ader-Nerseh in the plain of Ardaz, engaged it, and defeated it after a sharp struggle, in which the king, Sahag, particularly distinguished himself.