"We know that the Picts had a spoken language to complement the writing of the symbols, as Bede (a monk and historian who died in 735) writes that there are four languages in Britain in this time: British, Pictish, Scottish and English," lead author Rob Lee told Discovery News.
"We know that the three other languages were -- and are -- complex spoken languages, so there is every indication that Pictish was also a complex spoken language," added Lee, a professor in the School of Biosciences at the University of Exeter.
He and colleagues Philip Jonathan and Pauline Ziman analyzed the engravings, found on the few hundred known Pictish Stones. The researchers used a mathematical process known as Shannon entropy to study the order, direction, randomness and other characteristics of each engraving.
The resulting data was compared with that for numerous written languages, such as Egyptian hieroglyphs, Chinese texts and written Latin, Anglo-Saxon, Old Norse, Ancient Irish, Old Irish and Old Welsh. While the Pictish Stone engravings did not match any of these, they displayed characteristics of writing based on a spoken language.