The Duke of Aquitaine (Occitan: Duc d'Aquitània, French: Duc d'Aquitaine, IPA: [dyk dakitɛn]) was the ruler of the ancient region of Aquitaine (not to be confused with modern-day Aquitaine) under the supremacy of Frankish, English, and later French kings.
As successor states of the Visigothic Kingdom (418–721), Aquitania (Aquitaine) and Languedoc (Toulouse) inherited both Visigothic laws and Roman Law, which together allowed women more rights than their contemporaries would enjoy until the 20th century. Particularly under the Liber Judiciorum as codified 642/643 and expanded by the Code of Recceswinth in 653, women could inherit land and title and manage it independently from their husbands or male relations, dispose of their property in legal wills if they had no heirs, represent themselves and bear witness in court from the age of 14, and arrange for their own marriages after the age of 20. As a consequence, male-preference primogeniture was the practiced succession law for the nobility.
The Merovingian kings and dukes of Aquitaine had their capital at Toulouse. The Carolingian kings used different capitals situated further north. In 765, Pepin the Short bestowed the captured golden banner of the Aquitainian duke, Waiffre, on the Abbey of Saint Martial in Limoges. Pepin I of Aquitaine was buried in Poitiers. Charles the Child was crowned at Limoges and buried at Bourges. When Aquitaine briefly asserted its independence after the death of Charles the Fat, it was Ranulf II of Poitou who took the royal title. In the late tenth century, Louis the Indolent was crowned at Brioude.