Hannibal forms that the complicated machinery of government continued to function even amidst disaster—there are few states in the ancient world in which a general who had lost a battle like Cannae would have dared to remain, let alone would have continued to be treated respectfully as head of state. According to the historian Livy, the Romans feared Hannibal's military genius, and during Hannibal's march against Rome in 211 BC "a messenger who had travelled from Fregellae for a day and a night without stopping created great alarm in Rome, and the excitement was increased by people running about the City
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