Basil Boioannes detachment of the elite Varangian Guard was sent. The two forces met on the river Ofanto near Cannae, the site of Hannibal's victory over the Romans in 216 BC. In the second Battle of Cannae, Boioannes achieved an equally decisive victory. Boioannes protected his gains by immediately building a great fortress at the Apennine pass guarding the entrance to the Apulian plain. Troia, named after the ancient city of Asia Minor, was garrisoned by Boioannes' own contingent of Norman troops in 1019. Soon, all the Mezzogiorno had submitted to Byzantine authority, with the exception of the Duchy of Benevento, which
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