The Battle of Vosges, also referred to as the Battle of Vesontio, was fought on September 14, 58 BC between a coalition of Germanic tribes, under the leadership of Ariovistus, and a Roman army supported by Gallic allies under the overall command of Gaius Julius Caesar. This encounter is the second major battle of the Gallic Wars.

During the late 60s and early 50s BC several Germanic tribes had crossed the Rhine, seeking a home in Gaul. Feeling threatened, a number of Gallic tribes, allied to the Roman Republic, had petitioned the Romans to come to their aid. Gaius Julius Caesar, who was governor of the Roman province of Gallia Transalpina and who had just finished his campaign against the Helvetii, decided to continue his military campaign in Gaul and marched his army towards the migrating Germans.

Prior to the battle, Caesar and Ariovistus held a parley. Ariovistus' cavalry cast stones and weapons at the Roman cavalry. Caesar broke off negotiations and instructed his men not to retaliate to prevent the Suebi from claiming that they were induced into a trap by their accepting an opportunity to talk. The following battle resulted in a Roman victory, which secured the eastern borderlands of Gaul, and allowed the temporary construction of Caesar's Rhine bridges for a tactical punitive assault staged in western Germania.

In 61 BC, Ariovistus, chieftain of the Suebi tribe and a king from the Germanic peoples, resumed the tribe's migration from eastern Germania to the Marne and Rhine regions. Despite this migration encroaching on Sequani land, they sought Ariovistus' allegiance against the Aedui. In 61 BC, the Sequani rewarded Ariovistus with land following his victory at the Battle of Magetobriga. Ariovistus settled the land with 120,000 of his people. When 24,000 Harudes joined his cause, he demanded the Sequani give him more land to accommodate them. This demand concerned Rome because if the Sequani conceded, Ariovistus would be able to take all of their land and attack the rest of Gaul.

Following Caesar’s victory over the Helvetii, most of the Gallic tribes congratulated him and sought to meet in a general assembly. Diviciacus, the head of the Aeduan government and spokesmen for the Gallic delegation, expressed concern over Ariovistus' conquests and for the hostages he had taken. Diviciacus demanded that Caesar defeat Ariovistus and remove the threat of a Germanic invasion otherwise they would have to seek refuge in a new land. Not only did Caesar have a responsibility to protect the longstanding allegiance of the Aedui, but this proposition presented an opportunity to expand Rome's borders, strengthen loyalty within Caesar’s army and establish him as the commander of Rome’s troops abroad.

The senate had declared Ariovistus a "king and friend of the Roman people" in 59 BC, so Caesar could not easily declare war on the Suebi tribe. Caesar said he could not ignore the pain the Aedui had suffered and delivered an ultimatum to Ariovistus demanding that no Germanic tribesman cross the Rhine, the return of Aedui hostages and the protection of the Aedui and other friends of Rome. Although Ariovistus assured Caesar that the Aedui hostages would be safe as long as they continued their yearly tribute, he took the position that he and the Romans were both conquerors and that Rome had no jurisdiction over his actions. With the attack of the Harudes on the Aedui and the report that a hundred clans of Suebi were trying to cross the Rhine into Gaul, Caesar had the justification he needed to wage war against Ariovistus in 58 BC.

Caesar was not far away, probably at or near Bibracte, where he had just won a major victory over the Helvetii and other Celtic tribes, and had disposed of the remaining Boii, allowing them to settle in Aeduan land. As only small numbers of Boii were left after the battle, the Aedui were obliging. Caesar must have immediately begun marching up the Saône valley.

Ariovistus, being a skilled general in his own right, identified Vesontio as the key to the strategic Doubs valley and marched for it, but Caesar, probably relying on intelligence from the Gauls, arrived there first and established a main base. He had to combat a panic among his own men, who had heard that the Germans were some sort of superior warriors. Caesar called a meeting and then berated the centurions for making that necessary instead of just following orders. In one of his noted speeches he recalled them to duty and ended by threatening to march the next morning early with only the 10th legion, about whose valour he said he had no doubts at all. The speech had the intended effect of arousing fanatical loyalty in the 10th and shame and rivalry in the others.