A manuscript of Gregory the Great's (Pope Gregory I) Liber regulae pastoralis, or Regula pastoralis (Pope Gregory I) translated into English at the order of Alfred the Great, is the earliest surviving book written entirely in English. It is preserved in the Bodleian Library, Oxford. (Bodleian Library MS Hatton 20).
"This earliest English manuscript book is the only surviving book that can be linked to the King; it is his translation from the Latin into Anglo-Saxon of Pope Gregory’s work and bears a unique preface about the decline of learning among his people in the form of a letter from the King to Waerferth, Bishop of Worcester.
"The book represents a sophisticated approach to language and learning at a crucial time in the nation’s political and cultural development. It forms part of Alfred’s attempts to educate and rally his people through the use of edifying texts in the vernacular rather than in Latin, bringing them together in the face of an external (Viking) threat. This manuscript remained at Worcester until the late 17th century, when it was bought by the Bodleian from Robert Scot, as part of the collection of Christopher Hatton, 1st Baron Hatton" (http://www.bodleian.ox.ac.uk/news/2011_may_23, accessed 07-16-2011) .