[3] In 350, the emperor Constantius II (r. 337–361) gave Lucillianus command of the war against the Sasanian Empire, and, in this capacity, he successfully defended the fortress of Nisibis against Persian attacks.
[10] However, while lodged at the town of Bononia (Banoštor, Serbia) north of Sirmium, Lucillianus was surprised and captured in a night-time raid by Julian's troops; he was seized apparently while still asleep, and brought in a state of shock before the pretender.
[16] Jovian recalled his father-in-law to service and appointed him commander of the Roman armies in the praetorian prefecture of Italy, with the rank of magister equitum et peditum (master of cavalry and infantry),[17] instructing him also to proceed towards the imperial seat at Mediolanum (Milan) and secure the new emperor's authority in the western provinces.
[18][19] Jovian also took care to relieve the incumbent commander of the armies in Gaul, Jovinus, because, as a close supporter the emperor Julian, his loyalty to the new regime was apparently viewed as suspect.
[20][iii] His new nominee, Malarichus, refused the position however, and, upon hearing of it, Lucillianus (having by then arrived at Mediolanum) promptly hurried to Remi (modern Reims), capital of Gallia Belgica, to claim the military command for himself.