The true Ottone has arrived to claim his rightful kingdom and his bride, and has defeated the pirate Emireno, who is brought before him in chains. Emireno hints that he is really someone very mighty but refuses to reveal his true identity and is led away. (Aria: "Del minacciar del vento"). Ottone is now greeted by his enraged cousin Princess Matilda, who was officially engaged to Adelberto and is furious that he now proposes to marry Teofane instead. She informs Ottone that Gismonda and Adelberto are scheming against him. Ottone hopes that Teofane can still be his despite this (Aria: "Ritorna, o dolce amore"). Matilda, alone, yearns for revenge against Adelberto for his jilting of her (Aria: "Diresti poi così").