Wikipedia
Tarbelli
The Tarbelli were an Aquitani pre- Roman tribe settled in what today is southwestern France, in the region between the river Adour and the Pyrenees. The capital of the Tarbelli people was Aquae Tarbellicae, present-day Dax. They were the ancient inhabitants of Labourd, in the Northern Basque Country, in the present-day French department of the Pyrénées-Atlantiques.
Their historical territory today corresponds very well with the extension of the Lapurdian dialect of the Basque language. The Tarbelli, like all other Aquitanians, spoke an archaic form of the Basque language, known as Aquitanian language, whose dialects are unknown.