nobleman from the province of Moesia Superior, and Claudia, a niece of the emperors Claudius Gothicus and Quintillus. The same source also gives Claudius the nomina "Flavius Valerius" to strengthen his connection to Constantius. Modern historians suspect this maternal connection to be a genealogical fabrication created by his son Constantine I, and that his family was of humble origins. Constantine probably sought to dissociate his father's background from the memory of Maximian. Constantius was a member of the Protectores Augusti Nostri under the emperor Aurelian and fought in the east against the secessionist Palmyrene Empire. While the claim that he had been made a dux under the emperor Probus is probably a fabrication, he certainly attained the rank of tribunus within the army, and during the reign of Carus he was raised to the position of praeses, or governor, of the province of Dalmatia. It has been conjectured that he switched allegiances to support the claims of the future emperor Diocletian just before Diocletian defeated Carinus, the son of Carus, at the Battle of the Margus in July 285. In 286, Diocletian elevated a military colleague, Maximian, to the throne as co-emperor of the western provinces, while Diocletian took over the eastern provinces, beginning the process that would eventually see the division of the Roman Empire into two halves, a Western and an Eastern portion. By 288, his period as governor now over, Constantius had been made praetorian prefect in the west under Maximian. Throughout 287 and into 288, Constantius, under the command of Maximian, was involved in a war against the Alamanni, carrying out attacks on the territory of the barbarian tribes across the Rhine and Danube rivers. To consolidate the ties between himself and Emperor Maximian, Constantius divorced his concubine Helena and married the emperor's daughter, Theodora. Elevation as Caesar By 293, Diocletian, conscious of the ambitions of his co-emperor for his new son-in-law, allowed Maximian to promote Constantius in a new power sharing arrangement known as the Tetrarchy. The eastern and western provinces would each be ruled by an augustus, supported by a caesar. Both caesares had the right of succession once the ruling augustus died. At Mediolanum (Milan) on 1 March 293, Constantius was formally appointed as Maximian's caesar. He adopted Diocletian's nomen (family name) "Valerius", and, being equated with Maximian, also took on "Herculius". His given command consisted of Gaul, Britannia and possibly Hispania. Diocletian,