Ghostly faces, hidden from view for centuries, grace the bottom of this book from 1250. Image from The National Library of Wales via Huffington Post.

The Black Book of Carmarthen, written in 1250 and currently housed at at the National Library of Wales (or, sure, Llyfrgell Genedlaethol Cymru) is the oldest known medieval manuscript written entirely in Welsh, and even has some of the earliest references to King Arthur and Merlin. Now, researchers at The University of Cambridge have discovered “centuries’ worth of additional verse, doodles and marginalia which had been added to the manuscript as it changed hands throughout the years,” that had been erased by an owner in the 16th century.

Despite its importance and decades of scholarly research, the work of a PhD student from the University of Cambridge has revealed tantalising new glimpses of verse, and some images, from the 750-year-old book.

Myriah Williams and her supervisor Professor Paul Russell from Cambridge’sDepartment of Anglo-Saxon, Norse and Celtic, believe that a 16th century owner of the book, probably a man named Jaspar Gryffyth of Ruthin, summarily erased centuries’ worth of additional verse, doodles and marginalia which had been added to the manuscript as it changed hands throughout the years.

However, using a combination of ultraviolet light and photo editing software, the 16th century owner’s penchant for erasure has been partly reversed to reveal images, and snatches of poetry which are previously unrecorded in the canon of Welsh verse.

In addition to poetry and verse, ghostly faces can be seen peering out from the pages. The BBC spoke to Professor Russell about their discovery.

Although it was suspected there could be some text hidden within the pages, the researchers who first looked at the book under UV light were shocked when they found two faces staring out at them.

Prof Russell said: “It was a scary moment when we turned the page and out popped these faces in the bottom corner, along with a line of Welsh which goes with them.

“We think the line of Welsh was from one kinsman donating something, possibly the book, to another kinsman.”

They went on to discover a page of medieval Welsh poetry, which they believe has never been seen before.

They found a drawing of a fish on another page, and are continuing their search for other hidden text and images in the book.

Williams and Russell used a combination of ultraviolet light and photo editing software to uncover the hidden material.