Complex sentence: Margareta Leijonhuvfud was daughter of one of Sweden's most powerful noble families and engaged when the king decided to marry her; the engagement was broken for the sake of the king, and later her fiance was married to her sister instead.
Split into simpler sentences: Margareta Leijonhuvfud was daughter of one of Sweden's most powerful noble families and engaged when the king decided to marry her. The engagement was broken for the sake of the king, and later her fiance was married to her sister instead.