Medieval townspeople in western Europe during the period of the High Middle Ages needed protection from lawless nobles and bandits. The walled city was protection from direct assault, but once a townsperson left the city walls, he or she was at the mercy of often violent and lawless nobles in the countryside. Because much of medieval Europe lacked central authority to provide protection, such as a police force (to use a modern analogy), each city had to provide its own protection for citizens both inside the city walls, and outside. In order to do this towns formed what are called communes. 