Justinian (magister militum per Orientem)

[3][4][5] After this, Justinian and John (Germanus's son-in-law) were ordered to lead the army towards Salona (modern Split, Croatia), in preparation for a crossing over to Italy or an overland march to Venetia.

John remained in charge of the army until the eunuch Narses, who was appointed as the expedition's new commander-in-chief in early 551, arrived at Salona to take up command.

By 572, however, he had risen to the rank of patricius and was placed as commander-in-chief of the forces in the northeastern sector of the Empire's frontier with Sassanid Persia (magister militum per Armeniam).

[1][4] In 572, he supported the Armenian forces under Vardan III Mamikonian in their defence of Dvin, and, when the fortress eventually fell, in its recapture later in the year.

In this role, he set about training the numerous fresh troops raised by the Empire, and effected a reconciliation with the Ghassanid ruler al-Mundhir, restoring thus the traditional Byzantine alliance with his people.

When the shah entered into Byzantine Cappadocia and advanced towards Caesarea, Justinian gathered a superior army and blocked the mountain passes leading to it.

The Persians suffered heavy casualties, while the Byzantines captured great booty, including 24 war elephants which were sent to Constantinople.

[17][18] Returning to the capital, according to reports preserved exclusively in Western sources, Justinian was involved in a plot with the Empress Sophia over the succession of her husband, Justin II (r. 565–578), whose health was rapidly deteriorating.