The Great Hall is all that remains of the once important royal castle of Winchester. The hall was built 1222-36 for Henry III, and replaced an older hall that was demolished as part of Henry's remodelling of the castle. In 1302 a serious fire caused widespread damage to the royal apartments at the castle, which was deemed beyond repair, as a result the castle was no longer used as a royal residence. The Great Hall served an important legal and administrative role and continued to be maintained, but the rest of the castle gradually fell into decay.

In 1642 the Great Hall was sold to Hampshire's Justices of the Peace, while the rest of the castle had reached its final years. In 1645, Oliver Cromwell arrived in Winchester to besiege the castle which was being held by Royalist forces. After a week of heavy bombardment the castle surrendered, and what remained of the ruined fortress was demolished in 1649 so that it could no longer pose a threat.

The Great Hall served as a court until 1974, when new court buildings were opened allowing the hall to be restored, and visitors to view what is claimed to be the finest medieval Great Hall in England. Many people come to see the 18 feet in diameter Round Table of King Arthur, which hangs on the wall at one end of the hall. This isn't the real Round Table of legend, rather a version made for King Edward I (1272-1307), a king known for his interest in the Arthurian legend. Originally it was undecorated, but a young Henry VIII had it painted for a visit by Charles V, the Holy Roman Emperor.