From Alexandria to Antonio Panizzi, librarians have cherished the dream of containing the totality of written knowledge in one building. It is an attractive idea – a single place to ‘enquire within upon everything’ – but one realistically not capable of fulfilment, certainly not in the modern world. Librarians have therefore found other ways, both formal and informal, to access knowledge by sharing the resources of their libraries with each other. In the twentieth century, this practice has come to be called ‘library co-operation’ but it has a longer pedigree.

At the beginning of the fifteenth century, John Boston, a monk of Bury St Edmunds, compiled the Catalogus scriptorum ecclesiae, listing about 700 authors in English monastic libraries, a sort of medieval union catalogue. It was based on an earlier thirteenth-century Franciscan work, the Registrum librorum Angliae. In the seventeenth and eighteenth centuries various attempts were made, most notably at Oxford, to construct union catalogues of college library holdings, but these were largely unsuccessful. It was not until the twentieth century that ‘library co-operation’ as such became widespread in the United Kingdom. By then, municipal public libraries had been established for half a century and were under pressure from the demands of the burgeoning adult and technical education movements, university libraries were developing but not quickly enough, and industry and the professions were recognising an increasing need to access printed information. Simultaneously, the output of printed information was growing exponentially and no individual library or library system could hope to be entirely self-sufficient.