Constantine II was Roman Emperor from 337 to 340. Co-emperor alongside his brothers, his short reign saw the beginnings of conflict emerge between the sons of Constantine the Great, and his attempt to exert his perceived rights of primogeniture ended up causing his death in a failed invasion of Italy in 340.
The eldest, possibly illegitimate, son of Constantine the Great, he was born at Arles in February, 316, and raised as a Christian.
On March 1, 317 AD, Constantine was made Caesar, and at the age of seven in 323, took part in his father's campaign against the Sarmatians. At the age of ten he became commander of Gaul, after the death of his half-brother Crispus.
An inscription dating to 330 records the title of Alamannicus, so it is probable that his generals won a victory over the Alamanni. His military career continued when Constantine I chose his son field commander during the 332 campaign against the Goths.
Following the death of his father in 337, Constantine II initially became emperor jointly with his brothers Constantius II and Constans, with the Empire divided between them and their cousins, the Caesars Dalmatius and Hannibalianus. This arrangement barely survived Constantine I’s death, with the sons of Constantine arranging the slaughter of most of the family of Constantine I at the hands of the army. As a result, the three brothers gathered together in Pannonia and there on September 9, 337, divided the Roman world between themselves. Constantine, proclaimed Augustus by the troops received Gaul, Britannia and Hispania.