Oxford, Bodleian Library, Rawlinson B. 512 is an Irish vellum manuscript in quarto, numbering 154 folios and written in double columns by multiple scribes in the course of the late 15th and early 16th centuries. The compilation presents a diverse range of medieval texts in verse and in prose, some of which are in Latin, while the vast majority is written in the Irish language. It is a composite manuscript, consisting of five portions which were originally distinct volumes: I (fos. 101-22, 1-36, 45-52), II (fos. 53-75), III (fos. 75B-100, 37-44), IV (fos. 123-44) and V (fos. 145-54).