Waldman, Carl; Mason, Catherine (2006). Encyclopedia of European Peoples. Infobase Publishing. p. 38. ISBN9781438129181. The Aquitani [...] lived in Gaul in the region between the Garonne River and the Pyrenees in present-day southwestern France [...].
These are indeed the opening lines of Caesar’s account of his war in Gaul: Gallia est omnis divisa in partes tres, quarum unam incolunt Belgae, aliam Aquitani, tertiam qui ipsorum lingua Celtae, nostra Galli appellantur. Hi omnes lingua, institutis, legibus inter se differunt. Gallos ab Aquitanis Garumna flumen [...] dividit. Julius Caesar, De bello Gallico 1.1, edition of T. Rice Holmes