Battle of Cannae the flanks at the crucial moment, and encircle the overextended Romans. The Romans were in front of the hill leading to Cannae and hemmed in on their right flank by the river Aufidus, so that their left flank was the only viable means of retreat. In addition, the Carthaginian forces had maneuvered so that the Romans would face east. Not only would the morning sun shine low into the Romans' eyes, but the southeasterly winds would blow sand and dust into their faces as they approached the battlefield. Hannibal's deployment of his army, based on his perception of the terrain
Socii to raise a double-strength army of four legions and four "alae" e.g. at the Battle of Cannae in 216 BC, where each Consul commanded an army of about 40,000 men. Polybius states that the Romans and their allies could draw on a grand total of 770,000 men fit to bear arms (of which 70,000 met the property requirement for cavalry) in 225 BC, shortly before the start of the Second Punic War. The Romans reportedly asked their allies for an urgent register of all "men fit to bear arms" for a "tumultus Gallicus". Polybius' subtotals, however, are garbled, as he