The history of the island of Sardinia, relatively isolated from the European continent up into modern times, led to the development of a distinct Romance language, which even now preserves traces of the indigenous pre-Roman language of the island. The language is of Latin origin like all Romance languages yet the following substratal influences are possible:
Nuragic
Etruscan[citation needed]
Adstratal influences include:
Catalan
Spanish
Italian
...The early origins of the Sardinian language (sometimes called Paleo-Sardinian) are still obscure, due mostly to the lack of documents, as Sardinian appeared as a written form only in the Middle Ages. ...
Massimo Pittau claimed in 1984 to have found in the Etruscan language the etymology of many other Latin words, after comparison with the Nuragic language. If true, one could conclude that, having evidence of a deep influence of Etruscan culture in Sardinia, the island could have directly received from Etruscan many elements that are instead usually considered to be of Latin origin. Pittau then indicates that both the Etruscan and Nuragic languages are descended from the Lydian language, both therefore being Indo-European languages, as a consequence of the alleged provenance of Etruscans/Tyrrhenians from that land (as in Herodotus), where effectively the capital town was Sardis. Pittau also suggests, as a historical point, that the Tirrenii landed in Sardinia, whereas the Etruscans landed in modern-day Tuscany. Massimo Pittau's views however are not representative of most Etruscologists. ...
Linguists like Blasco Ferrer (2009, 2010) or Morvan (2009) have recently attempted to revive the theory of a Basque connection by linking modern surface forms such as Sardinian ospile "fresh natural cover for cattle" and Basque ozpil "id.", Sardinian arrotzeri "vagabond" and Basque arrotz "stranger", Sardinian arru "stone, stony" and Basque arri "stone", Gallurese (South Corsican and North Sardinian) zerru "pig" and Basque zerri "id.". Of interest, and in support to this theory, genetic data on the distribution of HLA antigens have suggested a common origin for Basque and Sardinian people....
The Roman domination, beginning in 238 BC, brought Latin to Sardinia, but this language was not able to completely supplant the Pre-Roman Sardinian language. Some obscure roots remained unaltered, and in many cases it was Latin that was made to accept the local roots, such as nur (in nuraghe, as well as Nùgoro and many other toponyms). Roman culture, on the other hand, became largely dominant; Barbagia derives its name from the Greek word Ό βάρβαρος-ου, which means "stuttering", due to the fact that its people could not speak Latin well. Cicero, who called Sardinian rebels latrones matrucati ("thieves with rough sheep-wool cloaks") to emphasise Roman superiority, helped to spread this conception.
Modern Sardinian, as it is known today, was the first language to split off from the others that were still developing from Latin, possibly as early as the first century BC.
...
During this time period, there was a reciprocal influence between Corsica and a limited area of northern Sardinia. On the southern side, though, the evidence favors contacts with Semitic and (later) Byzantine languages.
In the 1st century AD, some relevant groups of Hebrews were deported to Sardinia, bringing various influences; the Christianization of the island would probably have brought Hebrews to convert to a sort of independent cult of Sant'Antioco (perhaps a way to preserve some aspects of their ethnicity under a Christian form), still present in Gavoi. This contact with Hebrews, followed by another deportation of Christians, presumedly lasted for a couple of centuries, and makes it likely that by the 3rd century AD, Vulgar Latin began to dominate the island....
After this domination, Sardinia passed under the control of the Eastern Roman Empire, and more influences are derived from this culture. {This is what history claims.} The Greek language that was the main reference of Byzantines did not, however, enter into the structure of Sardinian (still a Romance language) except for in some ritual or formal formulas that are expressed in Latin using Greek structure. Much evidence for this can be found in the condaghes, the first written documents in Sardinian. {Which rather argues against any prolonged Byzantine influence.}
Some toponyms show Greek influence as well, such as Jerzu, commonly presumed to derive from the Greek khérsos (untilled), together with the personal names Mikhaleis, Konstantine, and Basilis. ...
The literature in this period is mostly made up by legal documents;...
The first document in which some elements of the language make their appearance, dates back to 1063: it is an act of donation to the abbey of Montecassino signed by Barisone I of Torres.