Siege of Segusio

Siege of Segusio
Part of Civil wars of the Tetrarchy
Roman Empire (311)
Date Spring of 312 Location Segusio, present-day Susa, in Piedmont, Italy. 45°08′00″N 7°03′00″E / 45.133333°N 7.05°E / 45.133333; 7.05 Result Constantinian victory
Belligerents
Constantinian forces	Maxentian forces
Commanders and leaders
Constantine the Great	Unknown
Casus belli: Avenge the death of Maxentius' father.

The siege of Segusio (Latin: Segusium) or siege of Susa was the first clash of the civil war between the Roman emperors Constantine the Great (r. 306–337) and Maxentius (r. 306–312) in the spring of 312. In that year, Maxentius had declared war on Constantine, claiming to intend to avenge the death of his father Maximian (r. 285–308, 310), who had committed suicide after being defeated by him. Constantine would respond with an invasion of northern Italy.^[1]

The siege of Segusio was the first of many battles that took place in the Italian peninsula, in all of them Constantine was victorious. With the capture of the city after subjecting it to a siege,^[2] the victorious emperor was able to continue his march through the interior of the peninsula until he reached Augusta Taurinorum, where he fought the Battle of Turin against the forces of Maxentius.^[3]