The Greek ethnographer Pytheas is credited with the first written mention of a word related to Priteni. Apparently, the Greek interpretation of the local name of the islands - at least to those who lived in the Cornish region - was Prettanike. It was the later Greek historian, Diodorus Siculus, who called Britain Pretannia. According to the historic model of the late T.F. O'Rahilly, the Priteni were the first Celts to inabit the British Isles. He argued that they settled in Scotland and Ireland some time between 700 and 500 BC, used iron and spoke a P-Celtic language similar to the Welsh and Cornish Brythonic languages. O'Rahilly also posited that the Priteni were the ancestors of the Cruithni. Recent academic theories, in connection with archaological evidence, consider the Cruithni to be a pre-Celtic, non-Indo-European speaking people, who were dominated by and/or willingly integrated into Celtic culture. Cruithni, or cruthen-túath is an Old Irish word, which possibly indicates they spoke a form of Proto-Celtic, generally regarded as the earliest Celtic language.* The first recording of the name Pict appears in a Latin panegyric written by Eumenius, in 297 AD. Picti is from the Latin word pingere, which means "paint" and was likely used to mean "painted or tattoed people." * It is important to note that the meaning of many Old Irish words are not entirely clear and are open to a particular scholar's interpretation. The best Old Irish languge experts can do is interpret a given word in the context in which it is written. That is not to say that their efforts can be ignored, but rather to be careful that your sources ARE scholarly. It is always best to read as many academic papers on any given subject as possible, and to consider both older and current theories. Articles by academics on the above subjects include: Evans, D. Simon (1964). A Grammar of Middle Welsh. Dublin: Dublin Institute for Advanced Studies Jackson, K., (1994). "Language and history in early Britain: a chronological survey of the Brittonic languages, 1st to 12th c. A. D," Celtic studies series, Dublin: Four Courts Press, ISBN 1 85182 140 6 McCone, Kim (1996). Towards a Relative Chronology of Ancient and Medieval Celtic Sound Change. Maynooth: Department of Old and Middle Irish, St. Patrick's College. ISBN 0-901519-40-5 O'Rahilly, T. F. (1946). Early Irish History and Mythology. Dublin: Dublin Institute for Advanced Studies Thurneysen, Rudolf (1946). A Grammar of Old Irish, Tr. D. A. Binchy and Osborn Bergin, Dublin: Dublin Institute for Advanced Studies See also the online essay, "Invisible Britons: the view from linguistics" by Richard Coates, University of Sussex