To this period of Umbrian greatness the evidently Italian names of the most ancient settlements in the valley of the Po, Atria (black-town), and Spina (thorn-town), probably owe their origin, as well as the numerous traces of Umbrians in southern Etruria (such as the river Umbro, Camars the old name of Clusium, Castrum Amerinum).

Such indications of an Italian population having preceded the Etruscan especially occur in the most southern portion of Etruria, the district between the Ciminian Forest (below Viterbo) and the Tiber.

In Falerii, the town of Etruria nearest to the frontier of Umbria and the Sabine country, according to the testimony of Strabo a language was spoken different from the Etruscan, and inscriptions bearing out that statement have recently been brought to light there, the alphabet and language of which, while presenting points of contact with the Etruscan, exhibit a general resemblance to the Latin.( 1) The local worship also presents traces of a Sabellian character; and a similar inference is suggested by the primitive relations subsisting in sacred as well as other matters between Caere and Rome.

It is probable that the Etruscans wrested those southern districts from the Umbrians at a period considerably subsequent to their occupation of the country on the north of the Ciminian Forest, and that an Umbrian population maintained itself there even after the Tuscan conquest.
In this fact we may presumably find the ultimate explanation of the surprising rapidity with which the southern portion of Etruria became Latinized, as compared with the tenacious retention of the Etruscan language and manners in northern Etruria, after the Roman conquest.

That the Umbrians were after obstinate struggles driven back from the north and west into the narrow mountainous country between the two arms of the Apennines which they subsequently held, is clearly indicated by the very fact of their geographical position, just as the position of the inhabitants of the Grisons and that of the Basques at the present day indicates the similar fate that has befallen them.