Complex sentence: Her paternal grandparents were William IV of Angoulême, Count of Angoulême and Marguerite de Turenne, and her maternal grandparents were Pierre de Courtenay and Elizabeth de Courtenay.
Split into simpler sentences: Her paternal grandparents were William IV of Angoulême, Count of Angoulême and Marguerite de Turenne. Her maternal grandparents were Pierre de Courtenay and Elizabeth de Courtenay.