This book analyses one of the few textual sources from twelfth-century England written in the vernacular: a manuscript now in Cambridge, University Library, bearing the shelf-mark li. 1. 33. It contains forty-two Old English texts, mostly saints’ lives composed by Ælfric, abbot of Eynsham (c.950-c.1010). Both palaeographical and linguistic evidence is used to establish the number of scribes and the possible origin of the various manuscript parts. A detailed examination of additions and alterations to the central part as well as a discussion of significant changes to the rest of the manuscript demonstrate language change and interest from the late twelfth century until today. The book includes the first study of three larger marginal passages, one in Middle English and two in Old French. Twelve plates taken from the manuscript and one from a related manuscript provide rich illustrations.