The Greek polis of Sparta had a very regimented structure. The full citizens of Sparta were required to be full-time soldiers, and their constant training made them warriors virtually without peer. Below the citizens were the Perioikoi, or militia. The Perioikoi trained only a few weeks a year and were deployed only within the local area as a defensive force. These part-time warriors made up about half of the Spartan army, but they did not have the rights of citizens.