Outside the town of Angers, King Philip of France walks with the Dauphin Louis, Constance, Arthur, and the Duke of Austria. Arthur and Constance thank Austria for joining the forces gathered against the English. Philip urges his men to ready themselves for an attack on Angers if the town doesn't swear allegiance to Arthur. Chatillon returns from his journey to England and urges Philip to turn the troops to a mightier battle, against the gathered English forces who are right behind him. Led by King John, who is accompanied by Eleanor and Lady Blanche of Spain, these forces are enormous and even include the bastard son of Richard the Lionhearted.
John enters with Eleanor, Blanche, the Bastard, and Pembroke. John offers peace to the French, but only if they accept his royal lineage. Philip too wishes John peace, but only if he takes his forces back to England without a fight and gives Arthur the crown of England. John asks Philip what has made him the judge of the situation, and Philip replies that heaven above has made him guardian of Arthur and a champion of his rights.
Eleanor interrupts, calling Arthur a bastard. Constant replies angrily, accusing Eleanor of infidelity to her husband, Henry II. Austria and the Bastard exchange insults, until Philip interrupts both parties. He lists Arthur's claims to John, which include full possession of English lands in Ireland and France. John says he would rather fight than lay down the throne. Eleanor calls to Arthur, trying to lure him away from the French, but Constance mocks Arthur to keep him in line. The sweet-tempered Arthur weeps, wishing he were not in the middle of the argument. Constance and Eleanor exchange harsh words again; Constance insists that the law says Arthur is the rightful king and accuses Eleanor of having committed adultery in giving birth to John, whom she again calls a bastard.
Philip silences them again and suggests that they ask the citizens of Angers whether they will accept John or Arthur's claim to the throne. John asks the citizens to open their gates, threatening destruction otherwise. Philip, speaking for Arthur, tells the citizens of Arthur's claim to the throne and asks that they accept him instead. The citizens acknowledge that they are England's subjects, but they will not open the gates until John or Arthur is able to prove they are the king. John offers his crown and his troops as proof of his leadership; Philip says as many men stand against him to contradict that claim. The citizens repeat their decision, so John and Philip urge their armies on and exit to battle.
A French and an English herald appear at Angers's gates, announcing the bloody outcome of the struggles and ask that the gates of the city be opened for their respective leaders. However, the citizens of Angers have seen that the armies are equally matched, neither able to prove itself superior. Therefore they will keep their gates closed until one side proves greater. Each king, with his train, reenters the scene, threatening to bring about the deaths of more soldiers in battle. They appeal to the citizens, who again refuse to open their doors.
The Bastard comments that the citizens of Angers flout both Philip and John, and they stand on their walls, watching the battle below like a play performed for them. He urges the two armies to merge temporarily and punish Angers for its audacity. Once they destroy Angers, they can break their alliance and continue to fight one another. John likes the suggestion, and Philip agrees. The citizens call to the kings and urge them not to follow this path of destruction, but instead to listen to another idea.