Paul-Yves Pezron (20 January 1639, Hennebont, – 9 October 1706, Brie) was a seventeenth-century Cistercian brother from Brittany, best known for his 1703 publication of a study on the common origin of the Bretons and the Welsh, Antiquité de la nation, et de langue des celtes.
[1] Pezron was a Doctor of Theology at the Cistercian College of St. Bernard in Paris and abbot of La Charmoie.
Pezron traced Welsh and Breton origins to the Celts of ancient writers, and traced the Celts further to eponymous hero-patriarchs from Gaul to Galatia.
Pezron believed the Welsh language came from a mother tongue called Celtick, a language that was only a theory to other authors.
Pezron's fairly unscientific book was popular and reprinted until the early nineteenth century.