Battle against the Nervians

Battle of the Sabis
Part of the Gallic Wars
Date 57 BC Location Gaul Result Roman victory
Belligerents
Roman Republic	Nervii Viromandui Atrebates Aduatuci
Commanders and leaders
Gaius Julius Caesar	Boduognatus
Strength
About 42,000 men (8 legions with cavalry and auxiliaries)	75,000
Casualties and losses
Unknown	Claimed 60,000 (based on body count which would include fleeing refugees who were being pursued across the river by Caesar's men)

The Battle of the Sabis, also (arguably erroneously) known as the Battle of the Sambre or the Battle against the Nervians (or Nervii), was fought in 57 BC near modern Saulzoir in Northern France, between the legions of the Roman Republic and an association of Belgic tribes, principally the Nervii. Julius Caesar, commanding the Roman forces, was surprised and nearly defeated. According to Caesar's report, a combination of determined defence, skilled generalship, and the timely arrival of reinforcements allowed the Romans to turn a strategic defeat into a tactical victory.

During the winter of 58-57 BC rumours came to Caesar's ears that the Belgic tribes were forming a union because they feared possible Roman interference in their affairs. The union included the Bellovaci, Suessiones, Nervii, Atrebates, Ambiani, Morini, Menapii, Caleti, Veliocasses, Viromandui, Aduatuci, Condrusi, Eburones, Caeroesi, and Paemani tribes, and was under the leadership of Galba, a king of the Suessiones. These reports provided Caesar with a good pretext for conquering more than Gaul "itself", and for this, he raised two legions in Cisalpine Gaul (XIII and XIV) and convinced the Remi tribe to side with him.

In response, the other Belgic and Celtic tribes had attacked Bibrax (the oppidum of the Remi, situated near the Aisne River). Caesar countered by defending the oppidum and winning an action at the Aisne. In the face of this and because of shortage of provisions, the union collapsed and tribal armies retreated to their own lands, with the agreed future intention of coming to the support of any tribe invaded by the Romans. Caesar continued his advance and tribes surrendered one by one. However, four tribes, the Nervii, the Atrebates, the Aduatuci and the Viromandui refused to submit.

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