Vahan, along with Vasak and Artaxias, was captured by the marzban of Armenia and was deported to Ctesiphon; sentenced to apostasy, and was "weakened in their faith," according to his childhood friend and contemporary historian Ghazar Parpetsi.

However, Adhur Gushnasp returned from refuge with a force of 7000 horsemen against the insurgents, he was, however, defeated and killed by Vahan and his army at the battle at Akori (northern slope of Mount Ararat).

[8] Crazed by the lack of promised reinforcements, the Armenians were defeated in 483 at the battle of Akesga[9] that among other consequences, caused the death of Sahak II Bagratuni and Vahan's brother, Vasak Mamikonian.

In the spring of 484, Shapur Mihran returned as the head of a new army and forced Vahan to flee to refuge near the Byzantine frontier, at Tao and Taron.

Struggling to suppress the revolt of his brother Zarir, Peroz's successor, Balash (r. 484-488), needed the help of the Armenians: in exchange for military support, he agreed to sign the Nvarsak Treaty, which granted religious freedom to the Christians and the prohibition of Zoroastrianism in Armenia, and included much greater autonomy for the nakharars.

According to John I Mandakuni and Babgeno, Christianity flourished during his reign;[11] churches were restored and rebuilt, most notably Vagharshapat (Etchmiadzin) Cathedral.