Legal Definitions - purgatory oath

A purgatory oath is a type of oath that was used in medieval times to determine the guilt or innocence of someone accused of a crime. The accused would swear an oath of innocence and then undergo a physical test, such as holding a hot iron or walking on hot coals. If they were not burned, it was believed that God had intervened and proven their innocence.

For example, if someone was accused of theft, they might be asked to swear a purgatory oath and then hold a hot iron. If they were not burned, they would be considered innocent.

This type of oath was eventually replaced by more reliable methods of determining guilt or innocence, such as trials by jury and forensic evidence.