This meticulous work seeks ‘to demonstrate how Anselm's letters have come down to us and how our surviving witnesses relate to one another. It also aims to define historical contexts within which the foundations of the textual traditions were laid as well as those in which our most important manuscripts were produced’ (p. 22). After surveying previous (often divergent, sometimes heated) traditions of scholarship on the letters (ch. i) and having outlined traditions of letter-writing and preservation in the eleventh and twelfth centuries in general (ch. ii), the author devotes the main body of the book (ch. iii) to examining in turn the major manuscript witnesses; shorter accounts of other collections (ch. iv) and the early printed editions (ch. v) follow. Pursuing a story of three different letter-collections made by Anselm himself (the first two at Bec, the third at Canterbury), the monumental ch. iii (pp. 74–225) works systematically though the relevant manuscripts, providing outline descriptions for each, sketching known or possible contexts for them, summarising the character of their texts, and indicating their relationships to other copies based on selective collation. As sigla (for manuscripts, lost copies and archetypes) steadily multiply, the result is a rather dense read, but anyone who stays the course is rewarded by a clearer view of the affiliations of the key manuscripts – albeit a view that, plausible and soundly-based as it seems, is very difficult to check, given that this is a study not an edition. Those unwilling or unable to stay the course may still be interested to know that Lambeth Palace Library, ms 59, the manuscript whose status has been most hotly contested in the past, is here (reasonably) ascribed to the 1120s and (more speculatively) associated with Eadmer of Canterbury. The brief conclusion is devoted to enunciating principles for re-editing Anselm's letters as a whole. If this might seem a logical next step, paradoxically the very thoroughness of the present work makes it difficult to see what could really be gained from the enormous labour that that would entail.