As the English Civil War ends during the mid 17th century, Oliver Cromwell (Tim Roth) begins seizing power along with his leader, Gen. Thomas Fairfax (Dougray Scott). The dethroned British king, Charles I (Rupert Everett), is held captive while Cromwell, Fairfax and their allies decide his fate. Although Charles attempts to win Fairfax's wife, Lady Anne (Olivia Williams), over to his side, and the ruler still has many loyalists, Cromwell is determined to see the king go to trial.