[1] The other Italic languages became extinct in the first centuries AD as their speakers were assimilated into the Roman Empire and shifted to some form of Latin.
Other Indo-European languages once spoken in the peninsula whose inclusion in the Italic branch is disputed are Venetic and Siculian.
[3][4] In the first millennium BC, several (other) non-Italic languages were spoken in the peninsula, including members of other branches of Indo-European (such as Celtic and Greek) as well as at least one non-Indo-European one, Etruscan.
It is generally believed that those 1st millennium Italic languages descend from Indo-European languages brought by migrants to the peninsula sometime in the 2nd millennium BC through Bell Beaker and Urnfield culture groups north and east of the Alps.
[10] This unitary theory has been criticized by, among others, Alois Walde, Vittore Pisani and Giacomo Devoto, who proposed that the Latino-Faliscan and Osco-Umbrian languages constituted two distinct branches of Indo-European.
This view gained acceptance in the second half of the 20th century,[11] though proponents such as Rix later rejected the idea, and the unitary theory remains dominant in contemporary scholarship.
[12] The following classification, proposed by Michiel de Vaan (2008), is generally agreed on,[13] although some scholars have recently rejected the inclusion of Venetic in the Italic branch.
[33] Italic peoples probably moved towards the Italian Peninsula during the second half of the 2nd millennium BC, gradually reaching the southern regions.
[6] At the start of the Iron Age, around 700 BC, Ionian Greek settlers from Euboea established colonies along the coast of southern Italy.
No relation has been found between Etruscan and any other known language, and there is still no clue about its possible origin (except for inscriptions on the island of Lemnos in the eastern Mediterranean).
But the evidence of Illyrian inscriptions is reduced to personal names and places, which makes it difficult to support such a hypothesis.
The Romanisation of the Italian Peninsula was basically complete by the 1st century BC; except for the south of Italy and Sicily, where the dominance of Greek was preserved.
All that is known about the linguistic landscape of Italy is from inscriptions made after the introduction of the alphabet in the peninsula, around 700 BC onwards, and from Greek and Roman writers several centuries later.
[38] An extreme view of some linguists and historians is that there never was a unique "Proto-Italic" whose diversification resulted in an "Italic branch" of Indo-European.
Some common features that seem to connect the languages may be just a sprachbund phenomenon – a linguistic convergence due to contact over a long period,[42] as in the most widely accepted version of the Italo-Celtic hypothesis.
[44] In medial position, all voiced aspirated stops have a distinct reflex in Latin, with different outcome for -*gʰ- and *gʷʰ- if preceded by a nasal.
In Osco-Umbrian, they generally have the same reflexes as in initial position, although Umbrian shows a special development if preceded by a nasal, just as in Latin.