Constantius I, Flavius Julius Chlorus (c. AD 250-306)

Roman emperor from 305, father of Constantine the Great. Constantius was the son of Illyrian parents and in 293 was adopted and appointed Caesar by the emperor Maximian, receiving the provinces of Britain, Gaul, and Spain. He was made Augustus on the abdication of the emperors Diocletian and Maximian 305 but he died in Britain at Eboracum (York) in the following year when on an expedition against the Picts and Scots.

Constantius defeated the Alemanni 298 and strengthened the Rhine frontier. He attempted to minimize the sufferings of his Christian subjects during the persecution of 303.