Book II

Caesar receives reports and letters that all the Belgae are forming a confederacy against Rome, threatening Roman control of Gaul.

Caesar raises two new legions and marches to the Belgae territories to meet the threat before it fully materializes.

The Remi, being nearest to Gaul proper, immediately submit to Roman protection and offer intelligence about the hostile Belgae coalition.

Caesar learns from the Remi that the Belgae are a formidable Germanic-derived people with over 300,000 armed men promised by various tribes to their confederation.

Caesar instructs Divitiacus and the Aedui to attack the Bellovaci territory, thereby dividing the Belgae confederation and preventing a unified enemy assault.

The Belgae attempt to ford the Aisne river to capture the Roman fort and cut off supplies, but are repelled with heavy casualties, forcing their retreat.

Faced with failed assaults, food shortages, and news of Aedui invasion of Bellovaci lands, the Belgae decide to disband and defend their own territories.

Caesar immediately pursues the disorganized Belgae retreat, using cavalry and legions to inflict massive casualties on the fleeing enemy.

Caesar moves against the Suessiones and compels their surrender through the rapid construction of siege works, compelling their submission through impressive Roman engineering.

The most powerful Belgae tribe, the Bellovaci, submit to Caesar after Divitiacus appeals for clemency, and Caesar demands 600 hostages as security.

Caesar learns that the Nervii are the most warlike Belgae, proudly reject surrender, and have prepared formidable hedge fortifications and ambush tactics.

Spies from the Belgae inform the Nervii of the gaps between Caesar's legions during march, prompting them to plan an attack on the vanguard.

Caesar describes the Sambre river valley terrain where the Nervii have positioned themselves with concealed forces ready to ambush the approaching Romans.

Caesar leads with six unencumbered legions followed by baggage, an order that contradicts Belgae intelligence and protects his main force from the planned ambush.

When the baggage train appears, the Nervii burst from concealment with incredible speed and ferocity, overwhelming Caesar's cavalry and threatening to rout the army.

Caesar demonstrates exceptional military leadership by moving among legions, personally encouraging soldiers, and issuing critical orders despite the chaos of a near-catastrophic ambush.

Caesar arrives at the tenth legion in the thick of fighting and delivers a brief encouraging address that reinforces the soldiers' resolve despite the enemy's proximity.

The Romans marshal their forces not according to standard military protocol but according to terrain and the exigency of the moment, with legions separated and vision obscured.

The ninth and tenth legions on the left wing drive the exhausted Atrebates across the river and pursue them aggressively despite disadvantageous positioning.

The eighth and eleventh legions similarly defeat the Veromandui and gain the higher ground, though the Roman left flank becomes dangerously exposed.

Roman auxiliary cavalry, camp-followers, and baggage handlers panic when they see the Nervii in the camp, spreading alarm and discouraging the Treviri auxiliaries.

Caesar observes his right wing in severe danger with heavy officer casualties and wavering soldiers; he seizes a shield and advances to the front line to rally the troops personally.

Caesar directs the tribunes to merge the seventh legion with nearby forces to create a stronger double-front formation and prevent encirclement.

The two rear legions and Labienus's captured enemy camp provide crucial reinforcements and a cavalry charge that revives Roman morale and breaks Nervii resistance.

Despite being overwhelmed, the Nervii continue fighting with exceptional bravery, standing on fallen comrades' bodies and hurling weapons from piles of corpses.

The Nervii are nearly annihilated with survivors reduced from 60,000 warriors to scarcely 500, and they send ambassadors to surrender unconditionally to Caesar.

Learning of the Nervii defeat, the Aduatuci abandon their march to aid and instead consolidate all their forces and possessions into a heavily fortified position.

The Aduatuci initially taunt the Romans from their walls regarding the Roman siege tower, questioning the ability of supposedly small Romans to operate such machinery.

When the tower moves toward their walls, the Aduatuci interpret this as evidence of divine Roman assistance and send ambassadors to negotiate surrender.

Caesar offers the same clemency extended to the Nervii but demands complete disarmament, which the Aduatuci agree to (though they secretly retain some weapons).

Despite surrendering, the Aduatuci secretly retain weapons and launch a surprise nighttime sortie from the town hoping Roman guards will be relaxed after the surrender.

Caesar's alert guards repel the Aduatuci nighttime attack, killing about 4,000; Caesar then sells the surviving 53,000 persons into slavery.

Caesar reports that his subordinate Crassus has successfully brought all the maritime Celtic tribes under Roman dominion without requiring Caesar's direct intervention.

With all Gaul now conquered, even Germanic tribes beyond the Rhine send ambassadors to promise submission, and Caesar returns to Italy after establishing winter quarters.