The daughter of René, King of Provence, who has been blind since birth, is unaware of her misfortune thanks to her father's diligence. She is betrothed to Robert, Duke of Burgundy. Her father hopes to restore his daughter's sight before the wedding with the help of a Moorish doctor. Robert and his friend Godfrey of Vaudemont, Count of Isonde, Champagne, Clervaux, and Montargis arrive at the castle. Robert is in love with Matilda, Countess of Lorraine, and wants to ask King René to break his promise. Vodemons sees the sleeping Jolanta, falls in love with her, and asks the king for his daughter's hand. Upon learning that Robert loves another, the king agrees to the wedding. The doctor's efforts are successful, the girl regains her sight and, happy, gets married.