Literary sleuths will find many clues about the creator of Sherlock Holmes from the letters in Arthur Conan Doyle, co-edited by the writer’s great-nephew Charles Foley.

When were you first exposed to the writings of your great-uncle?

I suppose the same age as most young people—I started reading Sherlock when I was 10-ish, and during my teenage years worked my way through the whole lot. I only became involved in the world of Holmes scholarship much later. I had been the black sheep of my family and was working on a master’s degree in London in the 1980s, and one day I just rang Jean Conan Doyle [Arthur’s daughter] and asked if I could come round for tea. This became an institution. When she died, and I began my duties as her executor, I became aware of the Sherlockian world.

Did your reading of these letters change your image of Doyle?

I got a stronger sense of him as a really decent man, which I was rather pleased to find. They also made clear that he and his mother had an incredibly close and loving relationship; they weren’t afraid to stand up to each other at times, but there was a huge fondness there. Also, Doyle had abandoned Sherlock Holmes after A Study in Scarlet and The Sign of the Four. From the book, you’ll learn that something happened which stimulated his interest in returning to the character, and he started work on the short stories.

How did Conan Doyle’s many letters to his mother survive?

Doyle’s mother, Mary, who obviously doted on him in particular of all her children, just kept them; after the deaths of Mary and her boys, there was a great deal of fighting among Doyle’s own children. The letters, and a bunch of other things, just vanished into storage for many years, in cardboard boxes in a corridor outside a solicitor’s office in London for about a quarter-century. The estate was finally settled in 1997, fortunately, shortly before the death of Dame Jean Conan Doyle. There were about a thousand letters, and anything of substance made it into the book.

What indications did the letters give you as to what Doyle thought were his greatest achievements?

In nonfiction, his book on the Boer War, which sought to present the British perspective. In fiction, it was his historical romances—Micah Clarke, The White Company—definitely not Holmes, and he was deeply disappointed that they didn’t sell as well as the Holmes stories.