From 1600 BC urban civilisation in Greece began to thrive and the power of a number of warlord states began to be felt around the Aegean. This period of Greek development and prosperity is called the Late Helladic or Mycenaean period, a time when Greek society was constantly geared for battle and invasion, and cities were fortress-like with extremely thick perimeter walls. Mycenae, Tiryns, Argos, Krisa, the Athenian Acropolis and Gla are all representative of the fortified citadels that dominated the Greek countryside for over 2000 years. This title charts the histories of the fortresses inhabited aby Homer's heroes, detailing their development, use in war and eventual decline.