This language was spoken in the lake region of northern Italy between 700 and 400 B.C.; however, it most probably was used before and after this date as well, though we have no existing proof of that. The Lepontic peoples lived along the periphery of a number of other groupings of people and in close contact with the Ligurians and Rhaetians (non-Indoeuropean tribes of the north part of Italy), in addition to the Etruscans and Venetians, and that is why their language is considered to be mixed in various ways with these others. Scientists agree to the statement that Lepontic Celts came here during one of the first waves of Celtic expansion over Europe and lived in the region until they were eventually assimilated by the expanded Latin (Roman) state (or by the later-arrived Senone Gauls, who represented the next major Celtic wave).
The tongue was written in an alphabet derived from Etruscan, quite unsuited to a Celtic language. For that reason, the phonetic interpretation of some forty inscriptions we have is not certain. We can only state that Lepontic was a P-Celtic tongue, but of a specific group different from both Brythonic and Goidelic. It had an extensive declension system, as can be seen from the following sample : Latumarui Sapsutaipe uinom nashom (For Latumaros and Sapsuta, wine of Naxos). This example shows the typical Indoeuropean system of noun declension with even one conjunction, -pe (Latin -que).
Gauls who came to Northern Italy in the early 4th century B.C. broke
up this balance of ethnic groups in the region. Soon nothing is to be heard
(or found) concerning the Lepontic language, and finally Romans assimilated
all language groups who had to this point lived here. And their languages
still remain a mystery to us.