Europe 357: Battle of Strasbourg
In late 356 Julian pushed back the Alemanni and recovered Colonia Agrippina (Cologne) from the Franks. The following year the Alemanni mounted a renewed offensive across the Rhine, but were decisively defeated by Julian at Argentoratum (Strasbourg).
356 Battle of Brumath▲
In June/July 356 Julian advanced in two columns to Durocortorum (Reims), then led his united army eastwards towards the Rhine, narrowly fighting off an Alemannic ambush on the way. After this close call, he made his way more cautiously to Brocomagus (Brumath), where he found a body of Alemanni prepared for battle. Adopting a crescent formation, he swiftly surrounded and defeated this force, putting the survivors to flight.
356 Recovery of Colonia Agrippina▲
After his victory over the Alemanni at Brumath, Julian traveled north to recover Colonia Agrippina (Cologne) from the Franks. Facing no resistance, he quickly took possession of the city and set to work restoring its defenses. Sufficiently cowed by the presence of the Roman army, the Franks agreed to peace.
356–357? Siege of Senonae▲
In late 356 Julian traveled south to winter at Senonae (Sens), distributing his army among several different towns in the region for supply purposes. Learning from deserters that this had left Julian isolated with a minimal force in Senonae, a huge body of Alemanni descended on the town and besieged it for 30 days before finally withdrawing. During this time, Julian’s magister equitum Marcellus was posted nearby but failed to come to the Caesar’s aid, leading Constantius II to replace Marcellus with the veteran general Severus in 357.
357 Danubian campaign of 357▲
In 357 the Marcomanni, Quadi, and Sarmatians crossed the Danube and began plundering Roman lands in the dioceses of Pannoniae and Dacia. Reports of these invasions reached Constantius II while he was in Rome; he hurriedly left that city in May and advanced into the Balkans, where he quickly drove off the invaders. However, the situation remained unstable and he would base himself in Sirmium for the next two years.
357 Alemannic attack on Lugdunum▲
In the spring of 357 Julian marched to Durocorturum (Reims) to join up with Severus’ army there, while Constantius II ordered his general Barbatio to lead 25,000 men to Augusta Raurica (Augst). The Romans intended to mount a pincer attack against the Alemanni but, just as they moved into place, a force of Alemanni broke through the gap between their lines and raided around Lugdunum (Lyon), although it proved unable to take the city itself. Julian immediately sent cavalry to intercept the invaders as they returned east and successfully captured a large number of them. However, others escaped back home, allegedly due to the negligence—or treachery—of Barbatio’s men.
357 Battle of Augusta Rauracorum▲
To drive the Alemanni from islands in the Rhine, Julian requested boats from his fellow commander Barbatio; Barbatio not only rejected this request, but proceeded to burn all the boats he had. While Julian was occupying the islands and rebuilding fortifications in the north, the Alemanni took advantage of the rift between the two leaders and fell in force upon Barbatio, driving him south of Augusta Rauracorum (Augst). This was enough to make Barbatio abandon the campaign and, after placing his army into winter quarters, he returned to the court of Constantius II.
357 Battle of Strasbourg▲
In the late summer of 357 Chnodomar and his fellow kings crossed the Rhine with 35,000 Alemanni near Argentoratum (Strasbourg) to confront Julian’s Roman army, now just 13,000-strong. Julian advanced to attack them and, despite Alemannic ruses that disrupted the Roman cavalry, Roman discipline eventually prevailed. By the end of the day, Chnodomar was Julian’s captive, and the Alemanni had lost over 6,000 men for a mere 247 Roman deaths. The Limes Germanicus had been restored.