According to Armenian sources, Izad Gushnasp was a member of the House of Mihran, and the son of a certain Ashtat.
However, according to the Iranian historian Ibn Isfandiyar, Izad Gushnasp and Ashtat were brothers from Daylam in northern Iran, but due to falling out with one of the most prominent and powerful noble of the Wuzurgan class in Daylam, had to leave the region and settle further east in Mazandaran.
[2] In 451, the Christian Armenians, who were under constant persecution by the Sasanian shah Yazdegerd II, revolted against the latter under their leader Vardan Mamikonian.
Izad Gushnasp, along with Ashtat, played a prominent role in the suppression of the revolt.
Izad Gushnasp is later mentioned as the commander of Bolberd, a fortress northeast to the city of Karin.