This is the first critical edition of the earliest and most important English translation of Mandeville's Travels. Its title, the 'Defective Version', derives from the loss of the second quire in the Anglo-French 'Insular' manuscript, or its antecedent, from which it was translated, containing part of the description of Egypt. Despite this loss of text, the Defective Version established itself as the dominant form of the work in England, and was perpetuated in the printed editions of the text until 1725.

The new edition is based on examination of all the extant manuscripts of the Middle English text and its French source, and so makes possible a more informed assessment of all other English versions. The textual commentary is based on a fresh investigation of the sources, and offers details for the first time of the author's indirect reliance on Marco Polo for much of his Asian relation.

This is the third in a proposed series of four versions of this widely influential collection of travellers' tales. M.C. Seymour has previously edited The Bodley Version of Mandeville's Travels, O.S. 253 [1963] and The Metrical Version of Mandeville's Travels, O.S. 269 [1973] for the Society.