The Battle of the Blarathon was fought in 591 near Ganzak between a combined Byzantine–Persian force and a Persian army led by the usurper Bahram Chobin. The combined army was led by John Mystacon, Narses, and the Persian king Khosrau II. The Byzantine–Persian force was victorious, ousting Bahram Chobin from power and reinstating Khosrau as ruler of the Sassanid Empire. Khosrau was swiftly reinstated upon the Persian throne, and as agreed upon returned Dara and Martyropolis. The Battle of the Blarathon altered the course of Roman-Persian relations dramatically, leaving the former in the dominant position. The extent of effective Roman control in the Caucasus reached its zenith historically. The victory was decisive; Maurice finally brought the war to a successful conclusion with the re-accession of Khosrau.