Siege of Autun

The siege of Autun was a conflict fought between the Roman Empire and the invading barbarian Alemanni tribe, who were ravaging Gaul, in 356 AD. The Romans successfully defended the city, and the barbarians retreated on the approach of reinforcements.During the Roman civil war of 350–353, Emperor Constantius II sought to increase pressure on his rival Magnentius by urging the Alemannic confederation to cross the Rhine and invade Magnentius' dominions in Gaul. The scheme was successful; the tribes under the command of Chnodomar and his allies invaded Gaul, defeating Caesar Decentius in the field, and besieging him in Sens. At the conclusion of the civil war, however, the Alemani declined to yield their conquests to the emperor, though he had granted them a commission to attack exclusively the rebels. Constantius entrusted Silvanus with driving the barbarians from Gaul and restoring Roman authority there. After the latter's revolt in early 355 AD, Constantitus elevated his cousin Julian to the title of Caesar of the Western Roman Empire on 6 November, 355. On the first day of December, Julian was sent from Mediolanum to assume his command. He resided in Vienne, on the Rhône river, during the winter of 355–356.

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