Barnard was George III’s librarian for much of his reign and remained in post throughout the reign of George IV. He is shown here with his catalogue of the king’s library.

In 1780 Barnard began an inventory of George III’s library at Windsor Castle. This systematically listed the books in the library by subject. Two copies of the inventory were produced, one to be kept at Windsor and another in London. The Windsor copy appears to have been a working document, with many manuscript additions listing books acquired after 1780. Several of these additions seem to have been written in the king’s own hand, suggesting that George III was very involved in the maintaining of an up-to-date reference collection at Windsor.