He ascended to the throne due to Artavasdes I not having an available heir, as well as his other brothers being kicked out of the royal estates by Artavasdes I. He was made (commander) over the western army by Artaxias I.

After the departure of Artaxias's most trusted general, Smbat Bagratuni, Tigranes's brother, Mazhan, requested King Artaxias that Artavasdes's and Tigranes's roles be stripped from the army and instead be entrusted to Zariadres. Artaxias