Rhaetic or Raetic (), also known as Rhaetian, was a language spoken in the ancient region of Rhaetia in the Eastern Alps in pre-Roman and Roman times. It is documented by around 280 texts dated from the 5th up until the 1st century BC, which were found through Northern Italy, Southern Germany, Eastern Switzerland, Slovenia and Western Austria, in two variants of the Old Italic scripts.
The German linguist Helmut Rix proposed in 1998 that Rhaetic, along with Etruscan, was a member of a language family he called Tyrrhenian, and which was possibly influenced by neighboring Indo-European languages. Robert S. P. Beekes likewise does not consider it Indo-European. Howard Hayes Scullard (1967), on the contrary, suggested it to be an Indo-European language, with links to Illyrian and Celtic. Nevertheless, most scholars now think that Rhaetic is closely related to Etruscan within the Tyrrhenian grouping.
Rix's Tyrsenian family is supported by a number of linguists such as Stefan Schumacher, Carlo De Simone, Norbert Oettinger, Simona Marchesini, or Rex E. Wallace. Common features between Etruscan, Rhaetic, and Lemnian have been observed in morphology, phonology, and syntax. On the other hand, few lexical correspondences are documented, at least partly due to the scanty number of Rhaetic and Lemnian texts and possibly to the early date at which the languages split. The Tyrsenian family (or Common Tyrrhenic) is often considered to be Paleo-European and to predate the arrival of Indo-European languages in southern Europe.
According to L. Bouke van der Meer, Rhaetic could have developed from Etruscan from around 900 BCE or even earlier, and no later than 700 BCE, since divergences are already present in the oldest Etruscan and Rhaetic inscriptions, such as in the grammatical voices of past tenses or in the endings of male gentilicia. Around 600 BCE, the Rhaeti became isolated from the Etruscan area, probably by the Celts, thus limiting contacts between the two languages.
The language is documented in Northern Italy between the 5th and the 1st centuries BCE by about 280 texts, in an area corresponding to the Fritzens-Sanzeno and Magrè cultures. It is clear that in the centuries leading up to Roman imperial times, the Rhaetians had at least come under Etruscan influence, as the Rhaetic inscriptions are written in what appears to be a northern variant of the Etruscan alphabet. The ancient Roman sources mention the Rhaetic people as being reputedly of Etruscan origin, so there may at least have been some ethnic Etruscans who had settled in the region by that time.
... adjoining these (the Noricans) are the Rhaeti and Vindelici. All are divided into several states.[a] The Rhaeti are believed to be people of Tuscan race[b] driven out by the Gauls; their leader was named Rhaetus.
Pliny's comment on a leader named Rhaetus is typical of mythologized origins of ancient peoples, and not necessarily reliable. The name of the Venetic goddess Reitia has commonly been discerned in the Rhaetic finds, but the two names do not seem to be linked. The spelling as Raet- is found in inscriptions, while Rhaet- was used in Roman manuscripts; it is unclear whether this Rh represents an accurate transcription of an aspirated R in Rhaetic, or is merely an error.