The commentary on Lamentations by the Benedictine historian, antiquary and classicist William of Malmesbury (c. 1090–c. 1143) is one of the author's later works and belongs to a direction in his writing that took him away from history and towards hagiography and works of monastic edification. That said, the Book of Lamentations was a peculiar choice for the scholar since it relies on reiteration and has no internal development, and William's comment on it is diffuse. His immediate source was the commentary by the Carolingian writer Paschasius Radbertus, but the range of patristic authorities that William summoned far surpassed those of his source, while his use of classical and late antique pagan authors set him apart from any other commentator of his age or before. He came to cite these authorities less and Paschasius more as his commentary progressed, as if he were tiring of the project and cutting his corners. The frequent exhortations to the reader (lector) make it clear that he envisaged his work, designed as a spiritual exercise, as an aid for the individual monk; written for local edification, it did not enjoy any sort of wide circulation in the Middle Ages, in spite of the author's fame. It is edited here from the two surviving manuscripts, Bodleian Library, Oxford, ms Bodley 868 (s. xii 2/4, from Worcester Cathedral Priory), and British Library, ms Cotton Tiberius A. xii (s. xii 2/4, perhaps from Eynsham Abbey). The two manuscripts are unrelated but Bodley 868 is perforce the basis for the edition since the Cotton manuscript was badly damaged in the Cotton Fire of 1731. Its deficiencies have been supplied where possible from excerpts made by Richard James, Sir Robert Cotton's librarian, before his death in 1638. This is the first edition of the commentary. It is a collaboration by two critics who have made a specialism of William of Malmesbury's surviving works. They hereby bring their achievement into the final straight; only William's Miracula beatae Mariae uirginis remain on their stocks. This edition, which is Winterbottom's work, conforms to the normal excellencies of the series and the editor's own superb standards. The text is given untranslated; there is an Index fontium and a scriptural index, while longer adnotationes are gathered after the text. The prolegomena on the witnesses is a model of lucidity, and there is a valuable contribution by Sigbjørn Sønnesyn that seeks to understand William's Christology as it is displayed in this elegant, diffuse and ultimately slightly puzzling text.