AQUITANIA Or, Aquitanica.
Roman province in southwestern Gaul.
The original Roman province, which was formed before Caesar’s conquest of Gaul, lay between the Pyrenees and the River Garonne below its confluence with the Tarn. It included the upper reaches of the Garonne, but the eastward sweep of the river, including Toulouse, lay beyond it.
With the conquests of Caesar and the organisation of the Empire under Augustus the name of Aquitania extended northwards and northeastwards towards the River Loire, though in general the province fell short of the river. However to the east of Bourges the Loire formed the boundary of the province, whilst both banks of its highest reaches were in Aquitania.
With the reorganisation of the Empire in the late 3rd century, Aquitania was divided into three provinces, all belonging to the diocese of Viennensis. Aquitanica Prima was formed from the northeast and east of the old province, the later Berry and Auvergne. The west and northwest became Aquitanica Secunda, and included the later Poitou and Périgord, and the lands either side of the Gironde. Most of the original Aquitania, the lands north of the Pyrenees, became Aquitanica Tertia, more commonly called Novempopulana, the land of nine peoples.
The late Roman provinces in Gaul became the ecclesiastical provinces of medieval France, where the Archbishops of Bourges, Bordeaux and Auch were the respective metropolitans of the three former Aquitanicas. The province of Bourges was divided in 1678, its southern dioceses forming the province of Albi.