Krzyzacy tells the story of a young nobleman, Zbyszko of Bogdaniec, who together with his uncle Macko of Bogdaniec returns from the war against the Order (Knights of the Cross) in nearby Lithuania. In a tavern inn Zbyszko falls in love with the lovely Danusia, who is traveling with the court of the Duchess Anna. He swears to her his knight's oath and promises to bring her three trophies from the Teutonic Knights.