In the midst of war in Constantinople against the Persians, Bajazet (Sultan Amurat's brother who is fighting in the war) is facing an ultimatum ; his brother has given orders to execute him (as Acomat tried to put him on the throne). In order to save his life, Roxane, the ruling Sultane in love with Bajazet, proposes to marry him. Pretending to return her affections, Bajazet loves an Ottoman Princess, Atalide and tries to stay alive without forsaking his love for Atalide.
