This is one of the major works of Anglo-Saxon prose, written by one of the foremost scholars of the time and the acknowledged master of prose style. The text is based on the Royal manuscript, which represents the earliest version of the text, and has corrections and annotation in Aelfric's own hand. All the early alterations to the Royal manuscript (amounting to more than 1000) and all substantive readings from other manuscripts, many of which reflect Aelfric's own revision, are recorded in the apparatus. A lengthy introduction describes all the manuscripts and analyzes in detail Aelfric's development of the text, the nature of his revision, and the distribution and copying of the text over the subsequent two centuries. A subsequent volume provides commentary and glossary for this text.