First Macedonian War Apollonia. Convinced that the entire Roman fleet was sailing to apprehend him, Philip ordered an immediate return to Cephalenia. Polybius speaks of "panic" and "disorder" to describe the fleet's hasty retreat and says that, in fact, the Romans had sent only a squadron of ten ships and that because of "inconsiderate alarm", Philip had missed his best chance to achieve his aims in Illyria, returning to Macedon, "without loss indeed, but with considerable dishonour". After hearing of Rome's disastrous defeat at the hands of Hannibal at Cannae in 216 BC, Philip sent ambassadors to Hannibal's camp in Italy to negotiate
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