Why was Aquitaine important to the Carolingian Empire?

Aquitaine was a vital component of the Carolingian Empire due to its strategic position and the necessity of maintaining control over a restive region. Incorporated into the empire by force, Aquitaine required constant supervision because it bordered the Spanish March, a dangerous military frontier that became increasingly volatile following Charlemagne’s 778 Spanish campaign.1

Beyond its defensive importance, Aquitaine served as a critical training ground for future leadership. By appointing his son Louis as king of Aquitaine in 781, Charlemagne established a subkingdom that allowed Louis to gain essential administrative and military experience over 33 years. During this time, Louis developed a network of loyal advisors, including southern clerics and officials, many of whom continued to hold significant influence throughout his later reign as emperor. The region also functioned as a distinct political entity with its own palaces, treasury, and mints, helping the Carolingians manage their vast, culturally diverse territories.1