Battle of Cannae the grandfather of Scipio Aemilianus, the patron of Polybius (one of the main sources of this history). In the spring of 216 BC Hannibal took the initiative and seized the large supply depot at Cannae, in the Apulian plain, placing himself between the Romans and their crucial source of supply. As Polybius noted, the capture of Cannae "caused great commotion in the Roman army; for it was not only the loss of the place and the stores in it that distressed them, but the fact that it commanded the surrounding district". The consuls, resolving to confront Hannibal, marched southward in
Early Middle Ages had broken down, and the Roman army comprised mainly barbarians and soldiers recruited for a single campaign. The general decline in discipline also led to the use of smaller shields and lighter weaponry. Not wanting to share the glory, Eastern Emperor Valens ordered an attack on the Therving infantry under Fritigern without waiting for Western Emperor Gratian, who was on the way with reinforcements. While the Romans were fully engaged, the Greuthung cavalry arrived. Only one-third of the Roman army managed to escape. This represented the most shattering defeat that the Romans had suffered since the Battle of Cannae (216