Constantine III (Western Roman emperor)

Constantine III
Coin of Constantine III
Roman emperor in the West
Reign	407–411
Predecessor	Honorius
Successor	Honorius
Alongside	Honorius (409–411) Constans II (409–411)
Died	411 (before 18 September)
Issue	Constans II Julian
Regnal name Flavius Claudius Constantinus
Religion	Nicene Christianity

Constantine III (Latin: Flavius Claudius Constantinus; died shortly before 18 September 411) was a common Roman soldier who was declared emperor in Roman Britain in 407 and established himself in Gaul. He was recognised as co-emperor of the Roman Empire from 409 until 411.

Constantine rose to power from within the field army of Roman Britain and was acclaimed emperor in early 407. He promptly moved to Gaul (modern France), taking all of the mobile troops from Britain, with their commander Gerontius, to confront bands of Germanic invaders who had crossed the Rhine the previous winter. With a mixture of fighting and diplomacy Constantine stabilised the situation and established control over Gaul and Hispania (modern Spain and Portugal), establishing his capital at Arles. The sitting emperor of the Western Roman Empire, Honorius, sent an army under Sarus the Goth to expel Constantine's forces. After initial victories, Sarus was repulsed. In Hispania, Honorius's relatives rose and expelled Constantine's administration. An army under the general Gerontius was sent to deal with this and Constantine's authority was re-established. In early 409 Honorius recognised Constantine as co-emperor. Constantine in turn raised his own oldest son to co-emperor as Constans II.

In 409 Gerontius rebelled, proclaimed his client Maximus emperor and incited barbarian groups in Gaul to rise up. Constans was sent to quash the revolt, but was defeated and withdrew to Arles. Meanwhile, Constantine invaded northern Italy, but his plan failed and he also pulled back to Arles. In 410 Constans was sent to Hispania again. Gerontius had strengthened his army with Germanic tribesmen and defeated Constans; the latter retreated north and was defeated again and killed at Vienne early in 411. Gerontius then besieged Constantine in Arles. Honorius appointed a new general, Constantius, who arrived at Arles while Gerontius was outside the city. Much of Gerontius's army deserted to Constantius, who took over the siege. A force attempting to relieve Constantine was ambushed. Constantine abdicated, took holy orders and – promised his life – surrendered. Constantius had lied: Constantine was killed and his head presented to Honorius on a pole.