Europe 351: Battle of Mursa Major
In late 350 Constantius II marched west to face the usurpers and quickly gained Vetranio’s surrender. He then turned on Magnentius and in September 351 narrowly defeated him at Mursa Major. However, with combined casualties of some 54,000, the battle—one of the bloodiest in Roman history—left both sides severely weakened.
25 Dec 350 Abdication of Vetranio▲
Proclaiming that the murder of his brother Constans must be avenged, Constantius II rejected Magnentius’ and Vetranio’s requests for recognition, and in December 350 marched his army into Serdica. Vetranio immediately backed down and was stripped of his imperial regalia by his troops, who joined Constantius’ ranks. In return, Constantius granted him a palace in Prusa (Bursa), where he lived out the remaining six years of his life in peace.
15 Mar 351 Constantius Gallus▲
As he prepared to face Magnentius in the West, Constantius II appointed his 24-year-old cousin Constantius Gallus, the son of Constantine I’s brother Julius Constantius, to the rank of Caesar. Gallus was married to Constantius’ sister Constantina and sent to govern the Prefecture of the East.
May 351–?? 352 Jewish Revolt against Gallus▲
At around the time Constantius Gallus arrived in Antioch in May 351, Isaac of Diocaesarea and the messianic figure Patricius launched a Jewish rebellion in Palestine, seizing control of much of the region. The revolt was put down the following year by Gallus’ general Ursicinus, who razed a number of the rebel towns and killed thousands of Jews of all ages. Ursinicus subsequently installed a permanent garrison in Galilee.
28 Sep 351 Battle of Mursa Major▲
In early 351 Magnentius ambushed and destroyed Constantius II’s reconnaissance force near the Italian border, encouraging him to invade Pannoniae. Assembling an army upwards of 60,000-strong, Constantius finally intercepted Magnentius, now with only 36,000 men, while the latter was besieging Mursa (Osijek) in September. The battle that ensued was long and brutal—Constantius lost 30,000 and Magnentius 24,000—but by nightfall Constantius had prevailed and his opponent fled west into Italy, narrowly avoiding capture on the way.