In 1426, the parliament was held in Leicester, in the Great Hall of Leicester Castle. At this time, a feud was going on between the Duke of Gloucester and a very powerful man called Beaufort. Because of this dispute, weapons were not allowed to be worn within the Great Hall of the castle, in order to prevent violence during the parliament. However, some partisan barons decided to conceal clubs or "bats" within their clothing. There were, in the end, no violent outbursts during the parliament. However, the parliament was later called The Parliament of Bats.

During the Parliament of Bats, the young King Henry VI, then only 5 years of age, was knighted, along with others in St Mary de Castro.

This wasn't the first or the last parliament to be held in Leicester. In 1414, the Fire and Faggot parliament was held in the hall of the Grey Friars Priory. Parliaments were also held in Leicester in 1421 and 1450, due to poor conditions in London. At that time, Leicester was quite an important city.