Late Basquisation

The "Late Basquisation" hypothesis set the historical geographical spread of the Basque or the proto-Basque language later in history.

It suggests that at the end of the Roman Republic and during the first centuries of the Empire, migration of Basque-speakers from Aquitaine overlapped with an autochthonous population whose most ancient substrate would be Indo-European.

[3] In his 2008 book Historia de las Lenguas de Europa (History of the Languages of Europe), the Spanish philologist and hellenist Francisco Rodríguez Adrados has updated the debate by arguing that the Basque language is older in Aquitaine than in the Spanish Basque country, and it now inhabits its current territory because of pressure of the Celtic invasions.

[4] According to the hypothesis of Late Basquisation, on top of a more ancient autochthonous Indo-European occupation, evidence appears of important Celtic establishments in the current territory of the Basque Country (though apparently not in the Pyrenean valleys of Navarre).

This is observed all over Álava and Biscay, thus being concluded that the Caristii and Varduli were not Basque tribes or peoples, but that they were Indo-Europeans like their neighbors Autrigones, Cantabri, and Beroni.