The King's Thief (1955)

Lady Mary's father is innocently accused of treason and is executed. It is the King's evil chancellor, the Duke of Brampton, who has found a way of getting rich by accusing wealthy nobles of treason, having them killed, and then expropriating part of their fortune along with their troops. Lady Mary travels to London to meet the Duke, and at the same time, meets the daring and handsome highwayman Michael Dermott. Dermott has stolen the Duke's notebook where the list of targeted noblemen has been written down. The Duke is very anxious to get his notebook back.