Ælfric, a monk at the Old Minster, Winchester, and Cerne in Dorset before becoming abbot of Eynsham in Oxfordshire was the most prolific and influential writer in English before Chaucer. Writing around the first millennium (while England was afflicted by the viking attacks that culminated in the Danish conquest of 1016), Ælfric used the rich theological education that he had received under Bishop Æthelwold at Winchester to devise a pedagogic programme encouraging his contemporaries (lay and clerical) to attend to the salvation of their souls. Scholars have long recognised the extent and diversity of Ælfric's written corpus, which includes Old Testament translations, summaries of world history, liturgical manuals, treatises on cosmology and time, saints’ Lives, homilies and commentaries on Scripture and on Christian doctrine. But before Aaron Kleist, no one has attempted to reconcile advances in Ælfrician scholarship since 1959, when Peter Clemoes published a comprehensive study of the contents and chronology of Ælfric's canon. This impressive and scholarly volume surveys three major aspects of ‘Ælfriciana’. First it establishes a new chronology for all his writings, tracing in detail the revisions and dissemination of individual texts (particularly the two series of Catholic homilies). Second, Kleist defines the content of the canon, redrawing boundaries to encompass twelve previously untitled texts, adding forty-two new ones and identifying at least thirty-four further items whose authorship remains contested. Finally, he provides a definitive list of manuscripts containing Ælfric's works, assigning a coherent set of sigla to the manuscripts and following established authorities in furnishing each with date, origin and provenance. Multiple tables summarise the information articulated in more discursive prose. The value of this study to scholars of Ælfric's writings – and indeed more generally to students of the doctrine and history of the tenth- and eleventh-century English Church – is inestimable. To take one example: a work from the third of eight categories into which Kleist has divided Ælfric's writings (non-liturgical narrative pieces), item 3.1.3: the Heptateuch. This translation of the first seven books of the Old Testament (only partly composed by Ælfric) is the earliest known attempt to make a continuous translation of the Old Testament into English. Kleist's entry supplies an overview of the text (commenting on the preface to Genesis that Ælfric addressed to one of his lay patrons, ealdorman Æthelweard, expressing anxiety about making Scripture available in the vernacular and discussing the literal and typological significance of the Old Testament); it dates the work (to different periods in the 990s); lists all the extant and now lost manuscripts in which the text was preserved in whole or in part; gives details of modern editions; lists facsimiles and digital images; and finally provides comprehensive notes on questions of date, authorship and style. Not, as the author notes, a book for reading on a quiet Sunday afternoon, this volume provides an essential point of reference for all elements of Ælfric's voluminous output and a starting point for numerous enquiries into the theology, liturgy and history of the English Church around the year 1000.