John Appleby came into being during a sea voyage from Liverpool to Adelaide. Ocean travel was a leisured affair in those days, and the route by the Cape of Good Hope took six weeks to cover. By that time I had completed a novel called Death at the President's Lodging (Seven Suspects in the U.S.A.) in which a youngish inspector from Scotland Yard solves the mystery of the murder of Dr. Umpleby, the president of one of the constituent colleges of Oxford University. It is an immensely complicated murder, and Appleby is kept so busy getting it straight that he has very little leisure to exhibit himself to us in any point of character or origins. But these, in so far as they are apparent, derive, I am sure, from other people's detective stories. I was simply writing a yarn to beguile a somewhat tedious experience—and in a popular literary kind at that time allowable as an occasional diversion even to quite serious and even learned persons, including university professors. (p. 11)

Appleby arrives in Oxford in a "great yellow Bentley"—which suggests one sort of thriller writing, not of the most sophisticated sort. But "Appleby's personality seemed at first thin, part effaced by some long discipline of study, like a surgeon whose individuality has concentrated itself within the channels of a unique operative technique." This is altogether more highbrow, although again not exactly original. And Appleby goes on to show himself quite formidably educated, particularly in the way of classical literature…. This must be regarded as a little out of the way in a London bobby lately off the beat. And there is no sign that Appleby is other than this; he is not the newfangled sort of policeman (if indeed such then existed) recruited from a university. Research in this volume will show that he is definitely not himself an Oxford man. (pp. 11-12)

What Appleby does possess in this early phase of his career is (I am inclined to think) a fairly notable power of orderly analysis. Had he been a professor himself, he would have made a capital expository lecturer. But I am far from claiming that he long retains this power; later on he is hazardously given to flashes of intuition, and to picking up clues on the strength of his mysteriously acquired familiarity with recondite artistic and literary matters. (p. 12)

What I am claiming here (the reader will readily perceive) is that Appleby is as much concerned to provide miscellaneous and unassuming "civilized" entertainment as he is to hunt down baddies wherever they may lurk. And I think this must be why he has proved fairly long-lived: and by this I mean primarily long-lived in his creator's imagination. In forty years I have never quite got tired of John Appleby as a pivot round which farce and mild comedy and parody and freakish fantasy revolve. (pp. 12-13)

[Appleby] is within a society remembered rather than observed—and remembered in terms of literary conventions which are themselves distancing themselves as his creator works. His is an expatriate's world. It is not a real world, controlled by actual and contemporary social pressures, any more than is, say, the world of P. G. Wodehouse.

But the sphere of Appleby's operations is conditioned by other and, as it were, more simply technical factors. Why does he move, in the main, through great houses and amid top people: what an Englishman might call the territory of Who's Who? It might be maintained that it is just because he likes it that way. We never learn quite where he comes from…. Eventually he makes a very convincing commissioner of Metropolitan Police, which is Britain's highest job in a police service. I'm not sure that he isn't more verisimilar in this role than he is as a keen young detective crawling about the floor looking for things. So one might aver that he finds his way into all those august dwellings because he fancies life that way.

But this isn't quite the fact of the matter. In serious English fiction, as distinct from a fiction of entertainment, the great house has long been a symbol—or rather a microcosm—of ordered society; of a complex, but on the whole harmonious, community. And indeed French, Russian, and American novelists have tended to see life that way; in the "English" novel the grandest houses of all have been invented by Henry James.

Something of this has rubbed off on the novel's poor relation, the detective story—the more readily, perhaps, because in England itself that sort of story was in its heyday rather an upper-class addiction.

But Appleby, like many of his fellow-sleuths in the genre, roams those great houses for a different and, as I have said, technical reason. The mansion, the country seat, the ducal palace, is really an extension of the sealed room, defining the spatial, the territorial boundaries of a problem. One can, of course, extract a similar effect out of a compact apartment or a semidetached villa. But these are rather cramping places to prowl in. And in detective stories detectives and their quarry alike must prowl. (pp. 13-15)

There is one other point that strikes me about him as I leaf through his chronicles. They are chronicles in the sense that time is flowing past in them at least in one regard. The social scene may be embalmed in that baronets abound in their libraries and butlers peer out of every pantry. But Appleby himself ages, and in some respects perhaps even matures. He ages along with his creator, and like his creator ends up as a retired man who still a little meddles with the concerns of his green unknowing youth. (p. 15)

Michael Innes, "John Appleby," in The Great Detectives, edited by Otto Penzler, Little, Brown and Company, 1978, pp. 9-15.