Novempopulania (Latin for "country of the nine peoples") was one of the provinces created by Diocletian out of Gallia Aquitania, being also called Aquitania Tertia. The area of Novempopulania was historically the first one to receive the name of Aquitania, as it was here where the original Aquitani dwelt primarily. Yet with the creation of a larger province with that name by Augustus Aquitaine began to signify a larger and more diverse territory. In the Middle Ages, it was the core region of the Duchy of Vasconia, later being split between the Duchy of Gascony and the County of Vasconia.
Provincial administration reformed by Diocletian, ca. 293. Praetorian Prefectures established after the death of Constantine I. Empire permanently partitioned after 395. Exarchates of Ravenna and Africa established after 584. Provinces replaced by Theme system, ca. 680.
* affected (boundaries modified/abolished/renamed) by Justinian's administrative reorganization in 534-536 † re-established after reconquest by the Eastern Empire in 534, as the separate praetorian prefecture of Africa