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
Religion in ancient Rome salted flour) and wine, then placed in the fire on the altar for the offering; the technical verb for this action was "porricere". Human sacrifice in ancient Rome was rare but documented. After the Roman defeat at Cannae two Gauls and two Greeks were buried under the Forum Boarium, in a stone chamber "which had on a previous occasion [228 BC] also been polluted by human victims, a practice most repulsive to Roman feelings". Livy avoids the word "sacrifice" in connection with this bloodless human life-offering; Plutarch does not. The rite was apparently repeated in 113 BC, preparatory to an