Under feudal law everyone, from the greatest baron to the poorest peasant, owed allegiance to the king. A criminal was someone who by doing something wrong, "had disturbed the king's peace".

Lords were responsible for punishing minor crimes in their local courts, but serious crimes were dealt with by justices appointed by the king from among his officials and trained lawyers. The sheriff had the job of rounding up criminals and keeping them in gaol before they were brought to trial.

Conditions there were usually very dirty and crowded and prisoners often died of diseases they caught in gaol before they got to trial. While in gaol the prisoner would rely on friends and family to bring them food or money, otherwise they may well starve. Charitable people sometimes left money in their will to help prisoners buy food.

Parliaments started to make laws to deal with specific problems such as highway robbery around the 14th century. In England, the parliament asked lords to cut down all the trees and bushes for 30 feet (approx 10 metres) on each side of major roads so that robbers would have nowhere to lie in wait for passing travellers.

The punishment for wrong-doing were very harsh in the middle ages. People who were guilty of lesser offences were fined or put in the stocks but those found guilty of serious crimes such as highway robbery, stealing livestock or treason and murder were executed. Executions were carried out in public and were often watched by large crowds.