Background
Born in Dardania, Constantius was the son of Eutropius, whom the Historia Augusta claimed to be a nobleman from northern Dardania, in the province of Moesia Superior, and Claudia, a niece of the emperors Claudius II and Quintillus.
Born in Dardania, Constantius was the son of Eutropius, whom the Historia Augusta claimed to be a nobleman from northern Dardania, in the province of Moesia Superior, and Claudia, a niece of the emperors Claudius II and Quintillus.
Constantius led a military career, serving as a staff officer at the imperial court, and in 293 was named Caesar (emperor designate). The new Caesar administered Gaul and Britain and suppressed rebellion in the latter province. Constantius became coemperor with Galerius in 305 upon the abdication of Maximian and Diocletian and died while on a military campaign the following year at Eboracum (York) in Britain.
A pagan of possibly monotheistic leanings, he leniently enforced in his provinces the persecution of Christians ordered by the emperors in 303.
Constantius was either married to, or was in concubinage with, Helena, who was probably from Nicomedia in Asia Minor. They had one son. In 289 political developments forced him to divorce Helena. He married Theodora, Maximian's daughter. They had six children.