Complex sentence: Her maternal grandparents were Frederick III, German Emperor, and the Empress Victoria, the eldest child of Prince Albert of Saxe-Coburg and Gotha and Queen Victoria of the United Kingdom.
Split into simpler sentences: Her maternal grandparents were Frederick III, German Emperor, and the Empress Victoria. Victoria was the eldest child of Prince Albert of Saxe-Coburg and Gotha and Queen Victoria of the United Kingdom.