'The National Library of Wales was founded to preserve the material of the literary culture and history of Wales, hence the number of medieval English language manuscripts is relatively small, and the manuscript context for some English texts is one in which Welsh is the main language. The best known of the Middle English manuscripts in the NLW are Brogyntyn II.1 (Porkington 10) and the Hengwrt manuscript for Chaucer's 'Canterbury Tales'; however, the collection has been little explored for its Middle English holdings, and of the manuscripts listed here fewer than half are included in the 'Index of Printed Middle English Prose'. They contain a wealth of materials, most notably in historical writings, scientific texts, and prophecies; among the texts not previously recorded are the 'Davies Chronicle' and a version of the 'Elucidarius'.'