The present publication may be considered as the foundation-stone of the Historical and Literary portion of the Philological Society's proposed English Dictionary. Its appearance in a separate form has been necessitated by the nature of the scheme, on which that work is being constructed. Without entering into details, which will be found in the Society's published Prospectus, [1] it will be sufficient for the present purpose to mention, that the raw material of the Dictionary, the words and authorities, are being brought together by a number of independent collectors, for whom it is consequently necessary to provide some common standard of comparison, whereby each may ascertain what he is to extract, and what to reject, from the author, or work, he has undertaken. This standard for works of earlier date than 1526 is furnished by the following pages, which contain an alphabetical inventory of every word found in the printed English literature of the 13th century. As, however, a mere index verborum would but inadequately fulfil its object, a certain amount of explanatory and etymological matter has been added, which it is hoped may render the work more generally interesting and useful than could otherwise have been the case. It is only proper to add that English literature, as distinguished from Semi-Saxon, is assumed to commence about the middle of the 13th century