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
Ancient history Ancient history Ancient history as a term refers to the aggregate of past events from the beginning of writing and recorded human history and extending as far as the post-classical history. The phrase may be used either to refer to the period of time or the academic discipline. The span of recorded history is roughly 5,000 years, beginning with Sumerian Cuneiform script; the oldest discovered form of coherent writing from the protoliterate period around the 30th century BC. Ancient History covers all continents inhabited by humans in the 3,000 BC – 500 AD period. The broad term Ancient History is