It was a geographical title applicable to a vast but ill-explored territory, rather than a real historical name of race or nation.

And so, in the earliest times, Gauls, Germans, Bretons, and even Iberians, appear frequently confounded under the name of Celts, peoples of Celtica.
Little by little this name is observed to become more restricted and more precise.

The Iberians of Spain are the first to be detached; then the Germans.

In the century preceding the Christian era, the Gauls, that is, the peoples inhabiting Gaul, are alone called Celts.

We begin even to recognize amongst them diversities of race, and to distinguish the Iberians of Gaul, alias Aquitanians, and the Kymrians or Belgians from the Gauls, to whom the name of Celts is confined.