Book of Llandaff

Llyfr Llan Dāv
Called in Latin Liber Landavensis also called in Welsh Llyfyr Teilo.

The Book of Llan Dāv is a medieval manuscript on 84 leaves of vellum, and in rather good condition, connected to the parish of Llan Dāv, circa 1150. It contains the lives of St. Dubricius, St. Teilo, St. Oudoceus, and St. Sampson, all of which were British saints of the fifth century near the end of the Roman occupation and the onset of the Saxon invasions. It then gives a list and short biographies of the bishops of Llan Dāv, as well as a papal bull of Honorius.

The Life of King Arthur by Joseph Ritson, ESQ. published by William Nicol, Cleveland Row, St. James, 1825, stated the the Book records a land grant to one "Noah" son of "Arthur" which was witnessed by Archbishop Dubricius. Which, if real, would place this Arthur in the correct time frame.  The "Arthur" recorded is apparently no longer living at the time this grant was executed and is not referred to as a king.

In 1840, the Welsh Manuscript Society produced a transcription and translation which was based on later MSS, which differ greatly from the twelfth-century Gwysaney MS. As Evans points out in his introduction, it is not known why the Society did not consult the earlier MS, since they did have access to it.

Reproduced from the Gwysaney MS., vol. iv. of the Series of Old Welsh Texts edited by J. Gwenogvryn Evans and J. Rhys, was released by Oxford in 1893. Evans, usually a reliable scholar, gives his theory that at least part of the book was written by Geoffrey of Monmouth. He uses handwriting analysis, as well as records of who was staying at Llan Dāv at the time.

Kenneth Jackson's Language and History in Early Britain, p.58, on the Book of Llandaff with charters in Latin with Welsh names interspersed gives an edition of the text The Text of the Book of Llan Dav (Oxford, 1893) by J. Rhys and J. Gwenogvryn Evans. Jackson was of the opinion from the forms of the Welsh that despite some attempts to see the Welsh as early forms, the dating of the book itself should be seen as 12th century.