King Edward IIIEdward, having been persuaded by Artois that he has rights in France, is about to mount an expedition there, when Lorraine brings a message from the French demanding Edward’s allegiance.
News also arrives of fresh invasions by the Scots King David, whose gains include the castle where Warwick’s daughter, the Countess of Salisbury, lives. David and Douglas are arguing over the spoils when the English army arrives and they flee.
Edward falls in love with the Countess, and asks his secretary Lodowick to write her a courtship letter on his behalf. Edward’s attempt to seduce her is rebuffed. He then invokes Warwick’s oath of loyalty to make him use his influence on her. Warwick reluctantly agrees, and is delighted when she maintains her opposition.
Edward, in an ill-humour at his lack of progress, is distracted by the arrival of his son, Prince Edward. He sees in his son’s face his wife’s image, and this makes him come to his senses. The Countess approaches him and threatens to kill herself unless he ceases his advances; but her offer is no longer required. Edward expresses respect for her courage, and leaves immediately for France.
The French King John and his son Philip greet their Bohemian and Polish allies, and are told of the arrival of the English fleet. The French are defeated at sea, but regroup on land. French citizens discuss prophecies of impending doom. The English army makes progress and they confront the French at Crécy. Edward and John parley, and Prince Edward is formally attired for his first battle. The French begin to flee, but the Prince is surrounded. Edward refuses to send him reinforcements, wishing him to prove himself. The Prince wins through, and is knighted.
The English then continue their pursuit of the French. Lord Mountford the Duke of Brittany wishes to support Edward, and asks Salisbury to carry a symbolic coronet to him. Salisbury needs a safe-conduct to pass through the French lines, and asks his prisoner Villiers to visit Charles Duke of Normandy to obtain it, trusting him to return. Charles tries to dissuade Villiers from returning, but Villiers keeps his word. On his way to Calais, Salisbury is taken by the French, but Charles persuades King John to let him continue. Prince Edward and Audley find themselves surrounded, but they reject three sarcastic French offers to yield.
The French army breaks up in disarray at the sight of ravens on the battlefield and the English use of flintstones as weapons - events which had previously been prophesied - and King John and Charles are taken. Meanwhile Edward has arrived at Calais, and received the town’s submission, having insisted that the citizens humble themselves.
Copland arrives from England, bringing King David as a prisoner. Salisbury also arrives, bringing the allegiance of Mountford, and reports his belief that Prince Edward is defeated. However, almost immediately the Prince arrives with the French prisoners. All parties then return to England.