Until quite recently, the words 'Cambridge Companion' and 'Crime Fiction' would have seemed mutually exclusive. Crime fiction was certainly written about, but on the assumption that readers and author were already dedicated fans, happy to ponder together the exact chronology of Sherlock Holmes's life-story or the mystery of Dr Watson's Christian name. Where the authors claimed some academic credentials, their love for the genre was owned up to as a guilty pleasure - W. H. Auden called it 'an addiction like tobacco or alcohol' - or juxtaposed to the world of 'proper' culture with tongue a fair way into cheek, as in Dorothy L. Sayers's demonstration that when writing the Poetics, what Aristotle desired 'in his heart of hearts . . . was a good detective story'.

Since the 1960s, however, the presumed barriers between ‘high’ and ‘low’ literature have been progressively dismantled. If only – at first – as indicators of a great many readers’ needs and anxieties, crime texts were increasingly seen as worthy of close analysis, and by now there are thousands of carefully argued, well-researched, elegantly written studies of the crime genre available and awaiting further comment. Like any new development this emergence has a specific history, any given intersection of which is likely to reveal different terminologies as well as different critical preoccupations. Up to the early 1980s, study of the form was still focused mainly on ‘detective’ or ‘mystery’ fiction, and nodded back to the half-serious ‘rules’ which had been drawn up for the genre in the inter-war period and stressed the figure of the detective and the author’s fair handling of clues. This tradition is well discussed in Stephen Knight’s chapter on ‘the Golden Age’ in the present book.