The 13th Century Book of Aneirin has been completely digitized and placed online. This is one of the four major Welsh mss. mostly known because it contains the text of Y Goddodin, an epic poem retelling the historic battle of Catraeth wherein 300 Men from Manaw Gododdin, near Edinburgh, fought the Saxons at Catraeth (modern day Catterick, North Yorkshire) around the year 600AD. Only three of the Britons survived the battle, one of whom, the poet Aneirin, commemorates the fallen.
This is the last of the Four Ancient Books of Wales to be digitized and made publicly available. The other three books are: