On 9 September 337 CE Constantine II, Constantius II, and Constans I succeeded their father Constantine I as co-emperors, dividing the Roman Empire between three Augusti. The tripartite division did not last long, as Costantine II soon attempted to assert his primogeniture. In 340 he invaded Italy in an attempt to conquer Constans’ territory, but the attack was unsuccessful and he was soon killed in an ambush near Aquileia.
Emperor Constantine I, Campidoglio, Rome
Emperor Constantius II, from Syria, Philadelphia: University of Pennsylvania Museum of Archaeology
Bust of Roman Emperor Constans, marble, second third of the 4th century. Paris: Louvre
Map: Division of Roman Empire among Constantine II (orange); Constans I (green); Dalmatius (yellow); and Constantius II (pale blue). Dalmatius was killed in 337 CE and his territory was divided between Constans and Constantius.
Constantine II, as Caesar. AV Solidus. Heraclea mint. Struck 326-330 CE: CONSTANTINVS IVN NOB CAES, laureate, draped, and cuirassed bust; obverse: VICTORIA CAESAR NN, Victoria advancing left, holding wreath and palm; SMH.
Constantius II. AV Solidus. Struck 337-347 CE. Antioch mint. FL IVL CONSTANTIVS PERP AVG, Pearl-diademed, draped and cuirassed bust; obverse: VICTORIA AVGUSTORVM, Victoria seated right on cuirass, inscribing VOT/XV/MVLT/XX in four lines on shield resting on knee and supported by a small genius; SMANΔ.