In his book, The Symbol Stones of Scotland (Orkney Press 1984), Anthony Jackson argues that the Picts were Celts who spoke a P Gaelic language related to Welsh. Not being a linguist, I cannot verify his claim, but there appears to be little dispute among scholars that the Picts spoke a P Gaelic language, while also borrowing Q Gaelic words. Evidence supporting this argument includes maqq/meqq, which apparently means son and is thought to be borrowed from Q Gaelic, and the "Pit-" in many Scottish place names is apparently cognate with the Welsh "peth" and the Irish "cuid".

I based my use of P Gaelic (Brythonic) for léine and brat on a passage from the 11th c. Magnus Berfeat saga (1093 AD). In this epic, King Magnus travels to the Western Highlands of Scotland (where my persona is from) and becomes intrigued with the native style of dress. He uses the words kyrtlu (which has been translated as "tunic") and yfir hafnir (upper garment) to describe their outfits, which is most likely the same combination of léine and brat that was worn by the Gaels in Ireland at the time. This seems like a reasonable conclusion in view of the strong connection the Western Isles of Scotland had with Ireland.

Having said the above, our knowledge of Pictish can be sketchy at best, as the only evidence we have of the language is a list of kings, the Ogham alphabet and a few inscriptions in the Roman alphabet. But you know what they say in the Ivory Tower: the more obscure the better! *g*

I would be quite interested in more information and other opinions on the Pictish language.