Louis was born in Chasseneuil-du-Poitou in the year 778 to Charlemagne and Hildegarde. Following Charlemagne's war with Aquitaine, he placed Louis in charge of the subkingdom in the year 781 with regnants. As he grew up in Aquitaine, he learned how to rule a kingdom and fight in wars, though he was known for being very devout and loyal to the Christian Church, ergo the nickname 'Pious'.