Adams’s daughters, in interviews about the book as part of the attendant publicity for the forthcoming BBC One adaptation, have been keen to play down any suggestion that their father was trying to allegorise. “‘Rubbish!’ he always said. ‘It’s just a story about rabbits.’”

Well it is, and it isn’t. When I wrote the introduction to the Penguin Modern Classics edition, I said “it is, inescapably, about rabbits” – but added that it is also very much inspired by his experiences in the second world war, and in particular his memories of two officers, Major John Gifford, a quiet but highly respected commanding officer (“he nearly always said please when he gave you an order”, according to Adams), and Captain Paddy Kavanagh, given to acts of astonishing bravado. These are, respectively, Hazel and Bigwig. (For good measure, the language rabbits speak, Lapine, has deliberate echoes of the Arabic he picked up during service in the Middle East.) And the Efrafa warren, run by the monstrous General Woundwort, is a pitch-perfect, and terrifying, description of a military dictatorship.

There has been some talk about how the new adaptation will tone down the violence and gore that upset so many viewers of the 1978 film adaptation; as I haven’t seen the new one, I can’t comment (I’ve seen the trailer, though, and the animation looks disappointing); but one thing I hope it will do is capture the timeless yet fragile beauty of the countryside around which it is set. The book may have episodes that upset and shock – Adams was an admirer of the Scottish-Canadian writer Ernest Thompson Seton, who pointed out in his own animal stories for children that no animal in the wild dies of old age – but it is also, partly, a meticulous portrait of the English countryside, in particular its flowers, which of course the rabbits, being at ground level, will notice even if they do not name them (although their own names are taken almost entirely from nature). But Adams does, and the very names achieve a kind of poetry, or the function of a musical soundtrack: Fleabane, Figwort, Dogwood, Purple Loosestrife, Burdock, Valerian, and countless more.

This is a book that inspired many, I have no doubt, to ecological awareness; indeed, the reason that Hazel and his companions leave the Sandleford warren in the first place is because his brother, Fiver, has a prophecy of imminent destruction by humans. As I write, West Berkshire council is contemplating a proposal to start building 1,000 new homes on Sandleford Park by 2020, which means that Fiver’s vision may well, finally, be fulfilled.