Louis the Pious, also called the Fair and the Debonaire, was King of the Franks and co-emperor with his father, Charlemagne, from 813. He was also King of Aquitaine from 781. As the only surviving son of Charlemagne and Hildegard, he became the sole ruler of the Franks after his father's death in 814, a position that he held until his death except from November 833 to March 834, when he was deposed.

Louis the German, also known as Louis II of Germany, was the first king of East Francia, and ruled from 843 to 876 AD. Grandson of emperor Charlemagne and the third son of Louis the Pious, emperor of Francia, and his first wife, Ermengarde of Hesbaye, he received the appellation Germanicus shortly after his death, when East Francia became known as the kingdom of Germany.