The politics involved in the opening of hostilities between Caesar’s legions and Vercingetorix’s armies are very complicated, and Rome and Gaul are both to blame. But Caesar considered and announced that Gaul had become a serious threat to Roman safety by 58 BC, and so he invaded with the intent to destroy and annex the entire territory. What happened next is famously recorded by Caesar himself, in his own hand, in his Commentarii de Bello Gallico. Assuming he told the truth, and he was remarkably honest and respectful of fine opponents, Vercingetorix, the primary leader of Gaul, has been given a well-deserved honorable mention below.
He beat Caesar fair and square at the siege of Gergovia, and the stage was set, after some 7 years of pitched battles, long marches and sieges, for the Battle of Alesia, in 52 BC. Caesar besieged the Gauls there with 12 legions, plus cavalry: at least 60,000 men. The Gauls had a garrison of 80,000, supplemented in a timely manner by at least 100,000 more troops under Commius, Vercingetorix’s ablest ally. He may have arrived with 250,000. Caesar had intended to starve the garrison into submission by building a circumvallation around the entire fort, but Vercingetorix managed to send a cavalry detachment through a gap in the wall as it was being constructed. Once it got away, Caesar anticipated a relief force arriving, and thus had a second wall built, called a contravallation, around the first, trapping themselves inside for protection. Now the besiegers were besieged and Caesar was in quite dire straits.
The weakest part of his wall was over a natural break in the northwestern area of the mountainous ground, and Vercingetorix desperately attacked in all directions from the inside, especially here, timing his action with an attempt by the relief force on the other side of the fort. Caesar’s army was flagging badly against both inner and outer assaults, and he inspired his men to redouble their efforts by personally leading a 6,000-horse cavalry charge around the Gallic relief force’s flank into its rear, and there was no mistaking the one and only great, crimson cape visible for miles on the battlefield. He had picked up a spear and shield, and was killing Gauls himself. Everyone on both sides knew to whom the cape belonged, and his men “burst frenzious with the joy of war,” as he wrote, and finally routed the relief army.
Once they began retreating in disarray, they were cut down by the thousands. Vercingetorix witnessed all this and surrendered the next morning.