Caesar, De Bello Gallico, 1.1.1f
by Tom Gardner
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.
Gaul is a whole divided in three, one of which is inhabited by the Belgae, another by the Aquitani, and the third by those called the Celts in their language, and the Gauls in ours. All these differ from one another with respect to their languages, institutions, and laws.