Monsignor Ronald Knox, sometime Roman Catholic chaplain at Oxford University (and the most brilliant of the four Knox brothers), kick-started the still booming Sherlock Holmes industry in 1911. Satirising a certain type of literalist biblical criticism, his Studies in the Literature of Sherlock Holmes analysed the text of Arthur Conan Doyle’s detective stories to show inconsistencies, which he partially attributed to the drinking of Holmes’s amanuensis, Dr John H Watson.

His humorously casuistic approach has been followed by a long line of literary scholars from Dorothy Sayers to John Fowles, who have debated such contentious matters of Holmes lore as which university the great detective attended and the nature of his literary tastes.

In the process they have delighted vast numbers