Flavius Valerius Julius Constantius

Also known as Constantius I
Roman Emperor (Augustus) 305-306
Roman Caesar 293-305

A native of Illyria born around the year 250, Constantius is more generally known as Constantius Chlorus or Constantius the pale. Although it was later claimed that he was descended from emperor Claudius Gothicus, this is now believed to be entirely fictional.

He followed a career in the Roman Army, rising through the ranks and serving as governor of Dalmatia until in 288 he became Praetorian Prefect to the emperor Maximian, who at that time shared power with the emperor Diocletian. In 289 Constantius married Theodora, Maximian's stepdaughter, a clear sign that he was being marked out for greater things. It therefore probably came as no surprise, when Diocletian created the Tetrarchy in 293, that Constantius was chosen as Caesar by Maximian and formally adopted as his son.

Constantius' main task as Caesar was to secure imperial control of Gaul, which was under severe pressure from the Franks, Saxons and Alemanni, and to deal with the rebel empire of Carausius that controlled Britain and the northern Gallic coast. During 293 Constantius successfully drove out the Franks and after blockading the harbour was able to force the surrender of the city of Gesoriacum (modern Boulogne). This was a severe blow to the rebel empire of Carausius, who was promptly assassinated and replaced by one Allectus.

He then spent the next two years consolidating his position in Gaul, whilst making preparations to invade Britain. In 296 his invasion force set sail, and despite bad weather was able to land in Britain, and restore the provinces of Britannia to the empire. In 298 Constantius was back on the continent driving back the Alemanni who crossed the Rhine and laid siege to Andematunum in Gaul (modern Langres in France). After which there appears to have been a period of relative calm in the west for once.

In 305 Diocletian decided to retire as emperor and forced Maximian to follow suit. Constantius and his fellow Caesar Galerius therefore automatically rose in rank to be Augusti, and joint rulers of the Roman Empire. Following the established practice of the Tetrarchy, Constantius then appointed Severus II as Caesar and adopted him as his son and therefore anointed successor.

Constantius had responsibility for the western dioceses, and like many emperors before and after was eager to begin his reign with the glory of military victory and conquest. A campaign against the Picts of Caledonia seemed to be in order, hence in 305 he was back in Britain leading another Roman foray into Caledonia (1). The actual detail of the campaign is unknown beyond the fact that it was conducted north of the Forth-Clyde line and that a victory over the Picts was claimed.

A further campaign the following year may have been his intention, but it was not to be. He died at Eboracum (modern York) on 25 July in the year 306.

Today he is remembered for his relative moderation in religous matters, (During the Great Persecution in 303 he seems to have limited himself to knocking down a few churches here and there.) and also because he was one of a succession of Danubian emperors that worked alongside Diocletian in restoring the fortunes of the Roman Empire after the dislocations and civil wars of the third century.

Of course Constantius is probably best remembered most for the fact that before he married Theodora he had a son, named Constantine with an innkeeper's daughter called Helena (2). This Constantine accompanied Constantius on his Pictish campaign of 305, and was present at Eboracum when he died. At which point Constantine was declared emperor by the British legions and is better known later as Constantine the Great.


(1) Some suggest that Britain was facing fresh incursions by the Picts and hence Constantius's campaign, others note that the Roman Empire often seems to have treated Britain as if it were a military training ground, and that Roman emperors needed little excuse for a quick campaign against some northern babarians in a relatively remote location were failure but by less noticable.

(2) It is unclear whether Constantius was actually married to Helena or not. The Catholic Encyclopedia unequivocally states that Helena "became the lawful wife of Constantius Chlorus". But then it would. Others aren't so sure and insist that Constantine was illegitimate.

Sourced from Roman Britain by Peter Salway - Oxford University Press (1991) together with information obtained from www.roman-emperors.org and www.roman-empire.net