the tyrant, emperor in Britain, Gaul, and Spain, was a common soldier in the Roman army stationed in Britain in the beginning of the fifth century of our aera, during the reign of the emperor Honorius. In A. D. 407 these troops rebelled, and chose one Marcus emperor, whom they murdered soon afterwards. They then swore obedience to one Gratianus, and having got tired of him, they killed him likewise, and chose one of their comrades, Constantine, in his stead. They had no other motive for selecting him but the fact that he bore the venerated and royal name of Constantine. Although little fitted for the duties of his exalted rank, Constantine considered that he should soon share the fate of his predecessors, if he did not employ his army in some serious business. He consequently carried his troops immediately over to Gaul, and landed at Boulogne. This country was so badly defended, that Constantine was recognized in nearly every province before the year had elapsed in which he was invested with the purple. (A. D. 407.) Stilicho, who was commissioned by the emperor Honorius, sent his lieutenant Sarus, a Goth, into Gaul, who defeated and killed Justinian, and assassinated Nervigastes. the two best generals of the usurper. Constantine was besieged by Sarus in Vienna, now Vienne in Dauphiné; but, assisted by the skill of Edobincus and especially Gerontius, the successors of Justinian and Nervigastes in the command of the army, he defeated the besiegers, and drove them back beyond the Alps. Upon this, he took up his residence at Arelatum, now Arles, and sent his son Constans, whom he created Caesar, into Spain. At the head of the Honoriani, a band of mercenary barbarians, Constans soon established the authority of his father in Spain (A. D. 408), and was rewarded with the dignity of Augustus.

In the following year Honorius judged it prudent to acknowledge Constantine as emperor, in order that he might obtain his assistance against the Goths. Constantine did not hesitate to arm for the defence of Honorius, having previously obtained his pardon for the assassination of Didymus (Didymius) and Verinianus (Verenianus), two kinsmen of Honorius, who had been killed by order of Constantine for having defended Spain against his son Constans; and he entered Italy at the head of a strong army, his secret intention being to depose Honorius and to make himself master of the whole Western empire. He had halted under the walls of Verona, when he was suddenly recalled to Gaul by the rebellion of his general, Gerontius, who, having the command of the army in Spain, persuaded the troops to support his revolt. In a short time, Gerontius was master of Spain; but, instead of assuming the purple, he had his friend Maximus proclaimed emperor, and hastened into Gaul, where Constantine had just arrived from Italy. Constans, the son of Constantine, was taken prisoner at Vienna, and put to death, and his father shut himself up in Arles, where he was besieged by Gerontius. This state of things was suddenly changed by the arrival of Constantius, the general of Honorius, with an army strong enough to compel Gerontius to raise the siege and to fly to the Pyrenees, where he perished with his wife. Constantius commanded part of his troops to pursue him; with the other part he continued the siege, as is related under CONSTANTIUS, and afterwards compelled Constantine to surrender on condition of having his life preserved. Constantine and his second son Julian were sent to Italy; but Honorius did not keep the promise made by his general, and both the captives were put to death. The revolt of Constantine is of great importance in the history of Britain, since in consequence of it and the rebellion of the inhabitants against the officers of Constantine, the emperor Honorius gave up all hopes of restoring his authority over that country, and recognized its independence of Rome,--a circumstance that led to the conquest of Britain by the Saxons. (A. D. 411.) (Zosim. lib. v. ult. and lib. vi., the chief source; Oros. 7.40-42; Sozom. 9.11_13; Jornandes, de Reb. Goth. p. 112, ed. Lindenbrog; Sidon. Apoll. Epist. 5.9; Prosper, Chron., Honorio VII. et Theodosio II. Coss, Theodosio Aug. IV. Cons.)