One of the most obvious reasons why legal historians have done so little to reclaim the wealth of historical material hidden in post-medieval legal manuscripts is that no one has been very sure just how much and what there is to be discovered. The largest collections of English legal manuscripts, excluding records, muniments and manorial records, are those in the British Museum (well over 1,000 legal volumes), Lincoln's Inn (over 990 volumes, not all legal), the Inner Temple (722 volumes, not all legal), Cambridge University Library (around 350 legal volumes), and the Harvard Law School (over 200 legal volumes). Only a small proportion of the items of legal interest have been individually described in print within the last century. Earlier cataloguers may be forgiven if they failed to foresee the importance of classes of manuscript which lawyers themselves had all but ignored; yet it is their work which is still our principal guide. The old catalogues are, with few exceptions, little more than lists of titles; at their worst they are positively misleading. Some large collections, such as the Ellesmere manuscripts in the H. E. Huntington Library, have no published catalogues at all.

The last few years have witnessed two noteworthy advances. In 1969 Dr Neil Ker published the first part of his Medieval Manuscripts in British Libraries, covering London libraries other than the British Museum.