Battle of Alesia
Caesar engaged in the Gallic Wars (58–50 BC), which led to his conquest of Gaul beyond Gallia Narbonensis. When the Helvetii, a federation of tribes from what is now Switzerland, planned a migration to the Atlantic coast through Gaul, Caesar went to Geneva and forbade the Helvetii to move into Gaul. While he went to Gallia Cisalpina to collect three other legions, the Helvetii attacked the territories of the Aedui, Ambarri, and Allobroges, three Gallic tribes, which called for Caesar’s help. Caesar and his Gallic allies defeated the Helvetii. The Gallic tribes then asked for Caesar to intervene against an invasion by the Suebi, a Germanic tribe. Caesar defeated the Suebi. In 57 BC he intervened in intra-Gallic conflicts and marched on the Belgae of northern Gaul. From then on he conquered the Gallic peoples one by one. His successes in Gaul brought Caesar political prestige in Rome and great wealth through the spoils of wars and the sale of war captives as slaves.
Roman–Etruscan Wars
The many similarities between accounts of the campaigns of 389 and 386 – in both Camillus is placed in command, defeats the Volsci and comes to the aid of Sutrium – has caused several modern authors to consider these to be doublets of each other. This was the view taken by Beloch who held that the Gallic sack had a severe and long-lasting effect on Rome's fortunes. Accordingly, Camillus' stunning victories against the Etruscans and Volsci so soon after must be inventions designed to minimize the scale of the Roman defeat. Different later writers then treated these invented victories in different ways, assigning them to different years with different incidental detail, until in Livy's writings they emerge as separate, but ultimately both unhistorical, events.