Arthur (Arthur, Duke of Britain):

He is the son of Constance and Geffrey, King John's older brother. According to the law of primogeniture, or birth order, Arthur ought to have become king of England when Richard I died. Arthur is generally presented as a helpless young child, yet sometimes he shows adult-like bravery and composure. At the opening of II.i, he greets the duke of Austria and graciously thanks him for joining the ranks of his supporters. Later in the scene, however, his poise deserts him in the face of the spiteful wrangling between Constance and Elinor, and he seems overwhelmed by the political turmoil swirling around him. When Constance learns that the marriage of Blanch and Lewis has brought peace between England and France, the depth of her outrage frightens Arthur, and he begs her to accept the situation.

Arthur's childish innocence and sweet temperament are highlighted...