Complex sentence: Her paternal grandparents were William II of Hesse and Anna of Mecklenburg-Schwerin, and her maternal grandparents were George, Duke of Saxony and Barbara of Poland, daughter of King Casimir IV Jagiellon of Poland and Elisabeth of Austria.
Split into simpler sentences: Her paternal grandparents were William II of Hesse and Anna of Mecklenburg-Schwerin. Her maternal grandparents were George, Duke of Saxony and Barbara of Poland, daughter of King Casimir IV Jagiellon of Poland and Elisabeth of Austria.