Glossaries are one of the most important sources for our knowledge of early medieval schools, for they provide an accurate records of what texts were studied and how they were understood. But they are also very difficult to access: countless glossaries lie unpublished in manuscript, the relations between them are unknown, and their origins are obscure. The most important contribution to solving these problems was made by Wallace Martin Lindsay (1858-1937), one of the greatest classical scholars ever produced in the British Isles, who in a pioneering series of articles identified the principal glossaries and clarified their relationships; he subsequently oversaw their publication in Glossaria Latina. So comprehensive was Lindsay's work that the subject virtually stood still for half a century; but recent advances in paleography and Insular Latin studies have drawn scholarly attention to glossaries once again. Any future work on glossaries must be based on Lindsay's pioneering articles; to facilitate such work, these articles have been provided with comprehensive indices of the Latin lemmata and sources of the glossaries, together with an account of recent work on medieval glossaries.