Historical crime mysteries must be good fiction with the added pleasures of time travel. In reality of course, the crime of the past was the same dreary catalogue of drunken quarrels and banal nastiness as that of the present - but art has many advantages over fact. However, a convincing historical background is sometimes difficult for a novelist to create because of the reader's preconceptions about the past. I was surprised by unrestrained sexual discussions among young women in Laurie King's A Monstrous Regiment of Women (HarperCollins, pounds 15.99) which is set in 1920, until I read Frances Spalding's biography of Duncan Grant, to find Vanessa Bell writing to Maynard Keynes that in his company "one can talk of fucking and sodomy and sucking and bushes and all without turning a hair". The date of this frank extract from the real world? 1914.

It shows the danger of complaining that details are not in period, but the historical murder mystery has to stand up to harsh scrutiny; the reader studies the text for clues to the mystery and for clues to the past, a level of textual attention to which only the most celebrated prose works in the language are normally subjected.

A Monstrous Regiment, set just after the First World War, provokes a further thought: what is the historical past? How far back do we have to go before an era seems "historical"? A Monstrous Regiment reminds us of how close the First World War still is to us; how modern were its people and its effects. This book is in a genre which is normally of rib-nudging coyness, the Sherlock Holmes spin-off, but here the young woman who narrates the story of evangelic fervour and drug addiction is a fitting match for the master. It's a novel which challenges the cliches of history.

At the opposite chronological extreme comes another of Lindsey Davis's series set in ancient Rome, Three Hands in the Fountain (Century, pounds 15.99), where something nasty keeps turning up in the aqueducts, while her cynical detective, Marcus Didius Falco, pounds through the mean tavernae in search of a serial killer who gets his fun outside the circus. Davis is strong on atmosphere, so although only a tiny percentage of her readers will have any idea of whether the details of ancient Rome are accurate, the rest of us are happy to take them on trust, carried along by the rush and fun of her writing.

PC Doherty's The Rose Demon (Headline, pounds 16.99) is one for medieval groupies suffering withdrawal symptoms after the death of Ellis Peters, who created the Brother Cadfael series. Much nastier things happen here, in Doherty's Gothicky tale of something unpleasant at large in 15th-century England. Doherty has a doctorate in medieval history and much academic debate goes on over whether there's any real difference between history and fiction. A working distinction might be that history is something a writer can mug up, but with fiction, if you ain't got it, you ain't got it.

And Carolyn Terry hasn't. My Beautiful Mistress (Little, Brown, pounds 16.99) drowns in a welter of cliches as the caddish murder victim, Vere Cavendish, bores his way through a family of stage-struck sisters. Curiously, the writing comes to life when Terry gets to grips with the Victorian theatre, the "Beautiful Mistress" of the title. I'd like to read a straightforward theatrical history by her: good history beats bad fiction.