The gate was designed by the medieval architect Master James of St. George on behalf of King Edward I between 1275 and 1279 to create a new water gate through which King Edward could enter the Tower by water. In the following centuries, the Tower of London was increasingly used as a prison for public enemies accused of treason and acquired its current name, Traitors' Gate, due to the large number of prisoners accused of treason who passed through the gate. The prisoners were taken by barge on the Thames under London Bridge, where the gruesome heads of recently executed prisoners were displayed on pikes.
During the Tudor period, such famous political prisoners as Edward, Duke of Buckingham, Queen Anne Boleyn, Sir Thomas More, Queen Catherine Howard, the tragic Lady Jane Grey, Seymour, Duke of Somerset, Princess Elizabeth (the future Elizabeth I), Robert Devereux, Earl of Essex, and James, Duke of Monmouth, the renegade son of Charles II, were imprisoned in the Tower.
Queen Anne Boleyn was arrested in 1536 on charges of treason, adultery, and incest. Sir Henry Norris and the queen's brother, George Boleyn, Lord Rochford, were arrested, accused of adultery with the queen, and taken by barge to the Tower of London, where they also passed through the Traitors' Gate.