Nothing is known of his early life, but Mihr-Mihroe is recorded as an old man by 555. He first appears in summer 530, during the Iberian War, when he led an army of 30,000 in an invasion of Byzantium's Armenian provinces. However, he was defeated near Satala by the Byzantine generals Sittas and Dorotheus and had to withdraw. In summer 531, following the narrow Persian victory at Callinicum and a series of minor reversals in Armenia and northern Mesopotamia, the Persian shah, Kavadh I (r. 488–531), sent Mihr-Mihroe along with Bawi and Kanarang to capture the Byzantine stronghold of Martyropolis. The two commanders laid siege to the city, but after receiving news of Kavadh's death, and with their troops suffering from the cold winter, they concluded a truce and withdrew to Persian territory.