The main contents of the Bosworth Psalter (BM Add. 37517; henceforth cited as B) are on palaeographical grounds commonly assigned to the last quarter of the tenth century. It is thus the oldest surviving English manuscript in which all the important texts of the Benedictine Office – psalter, canticles, hymns and monastic canticles – have been placed together. These texts are preceded by a calendar of slightly later date. Parts of the psalter and six of the canticles were glossed in Old English very early in the eleventh century and there are Latin additions contemporary with the Old English gloss – a short litany, prayers and mass-texts. Finally some psalms were heavily annotated in Latin in the twelfth century. B, still bound in its original oak covers, is of considerable interest on several counts. Early English psalters supply a very good text of the Psalterium Romanum, and B is one of those which appear in the apparatus of Weber's new edition. The hymnologist appreciates B as the oldest representative of the ‘New Hymnal’ in England. And the art historian values it both for its initials to the psalms, which display a style different from that of the contemporary Winchester School, and for the full-page figure of Christ on 128v. Hence any light that can be thrown on the place of origin of this manuscript is important to several disciplines.