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
Slavery in ancient Egypt Slavery in ancient Egypt Slavery in ancient Egypt existed at least since the New Kingdom (1550-1175 BC). Discussions of slavery in Pharaonic Egypt are complicated by terminology used by the Egyptians to refer to different classes of servitude over the course of dynastic history. Interpretation of the textual evidence of classes of slaves in ancient Egypt has been difficult to differentiate by word usage alone. There were three types of enslavement in Ancient Egypt: chattel slavery, bonded labor, and forced labor. Chattel slaves were mostly captives of war. All captives, including civilians not a part of the military forces, become