Aquitania, the southwestern division of ancient Gaul, situated between the Garonne, the Pyrenees, and the bay of Biscay. It was the smallest of the earlier divisions of Gaul, and Augustus, in order to equalize it in some measure with the other two, extended its frontier to the Loire. The language, institutions, and physical conformation of the Aquitani were different from those of the other inhabitants of Gaul, and proclaimed their affinity with the Iberian tribes of the Spanish peninsula. Aquitania, or Aquitaine, was an independent duchy under the Merovingian and Carlo-vingian dynasties, though Charlemagne reduced it to temporary subordination. By the marriage of Louis VII. with Eleanor of Aquitaine, it became united to the French monarchy in 1137; but 15 years later the same princess, having been divorced from Louis, married Henry Plantagenet (afterward Henry II. of England), and transferred the possession of Aquitaine to her new husband. The title to the duchy was disputed by England and France for many years, but Charles Y1I. finally reunited it to the French crown in 1453, In the 13th or 14th century the name became corrupted into Guienne. (See Guienne.)