There should be a special name for books about World War One in which World War One doesn’t feature. I mean novels such as Ernest Hemingway’s Fiesta, Evelyn Waugh’s Vile Bodies and (except for two glancing references) F. Scott Fitzgerald’s The Great Gatsby. Novels, in other words, where the trenches are a constant, brooding, unmentioned horror.

I’d add another classic to that list: J.R.R Tolkien’s The Lord of the Rings. Although Tolkien used to get cross with anyone who suggested that his books were allegorical, he admitted that “the Dead Marshes and the approaches to the Morannon owe something to Northern France after the Battle of the Somme.” Tolkien served as a junior officer in that abomination, whose centenary we mark this week.