Defence in depth in order to retreat successfully, and they assume that the defender's morale will recover from the retreat. A possible early example of this came at the Battle of Cannae in 216 BC, when Hannibal employed this manoeuvre in order to encircle and destroy eight Roman legions, but that is disputed by some historians. Edward Luttwak used the term to describe his theory of the defensive strategy employed by the Late Roman army in the 3rd and 4th centuries AD. Later examples of defence in depth might be European hill forts and the development of concentric castles. In those examples, the
Battle of the Bagradas River (255 BC) Battle of the Bagradas River (255 BC) The Battle of the Bagradas River (the ancient name of the Medjerda), also known as the Battle of Tunis, was a Carthaginian victory over Rome in the spring of 255 BC during the First Punic War. The greatly superior cavalry of the Carthaginians and their allies permitted a pincer attack on the Roman infantrymen, provoking a rout and slaughter. The mercenary Spartan general Xanthippus was hired by the city of Carthage following heavy-handed negotiations by Rome. He made the Romans fight on open ground, which allowed him to maximise the effect of the