With their bad-boy behaviour and instantly identifiable art, the pre-Raphaelites have become a permanent fixture in middle-brow culture. Images from their stylised paintings of mythical and biblical subjects circulate endlessly on book jackets and biscuit tins and probably still get tacked up on the walls of high-minded teenagers. The kind of women the PRB liked to paint - all bruised mouth and waterfall hair - have become a visual shorthand for the movement as a whole. And the stories of their triangular entanglements are so familiar as to be almost the stuff of fable: Ruskin, Millais and Effie; Burne-Jones, Georgie and Mary Zambaco; Rossetti and just about anyone he clapped eyes on. As for their wallpaper, well, it's an unusual Englishwoman who hasn't soothed herself to sleep imagining what her sitting room would look like layered with something from the William Morris back catalogue.

So it is disconcerting to learn on the first page of Franny Moyle's study that she sees her goal as bringing "the pre-Raphaelites to life for a new public". Where, you wonder, did the old public go? And how is she going to locate the pocketful of people who are not already on nodding terms with images drawn from the walls of Andrew Lloyd-Webber's study, which is where all pre-Raphaelite art goes in the end? The answer turns out to be, "through the telly". For Moyle's book is a BBC2 tie-in, designed to accompany what promises to be a sumptuous romp through the "private lives" (not too much boring old art then) of the pre-Raphaelite Brotherhood and the swan-necked shopgirls whom they elevated into icons.

And on these terms, it succeeds. The narrative weaves together at least a dozen individual stories without showing the joins. Particularly impressive is the way Moyle returns to a key moment - Lizzie Sidall's suicide, for instance - at various points to consider it from different angles. In less sure hands this would feel repetitive, but Moyle has the perception to see that Sidall's unhappy end impacted on several other stories: that of the relationship between her husband Rossetti and his rock-like brother William, the friendship between Swinburne (who'd had dinner with the couple on that fateful night) and Rossetti, not to mention the growing love affair between Rossetti and his public (just one reason why the inquest produced a tactful verdict of death by misadventure). All of which makes it a shame that Moyle has been let down so badly by her proofreaders. The book bristles with typographic mix-ups. At one point we are even told that Rossetti used to get himself to sleep with "choral" (for "chloral"), which at least sounds more soothing than the laudanum that sent poor Lizzie to her grave.

Particularly deft is the way Moyle integrates the "private life" of Ruskin into her story. Since Ruskin was a critic rather than a practitioner, and his professional activities extended far beyond his early championing of the group, his story tends to get hived off from that of the roaring boys who painted their way to prominence. If Ruskin appears at all in such accounts, it is usually as the impotent mama's boy whose marriage to Effie Gray was scandalously annulled in 1854, clearing the way for Millais to provide her with a happy ending: marriage to an important public man and a brood of pretty children.

But Moyle does not drop Ruskin's story there, instead taking it on to its bitter third act. In 1858, the 40-year-old Ruskin once again became obsessed with a young girl, this time an 11-year-old called Rose La Touche. The next 17 years were spent in a war of attrition in which the two unlikely love birds flirted, fell out, planned for marriage, stalked each other through the post and in person, bored their friends and family, and wore each other down until each was only a fraction of their former selves. Rose eventually died at the age of 27 in Ruskin's arms, having spent years starving herself into an approximation of the pre-pubescent with whom he had first fallen in love.

It was a sad ending, but no sadder than what happened to Rossetti and his one-time protégé William Morris. Having tortured each other with their mutual love for Janie Burden, an Oxford slum girl who had exactly the kinky hair and bee-stung lips that qualified her as a "stunner", the two men drifted apart. The mutual lease on Kelmscott was given up (Morris craftily got sole possession back almost immediately) and Rossetti racketed around his house in Cheyne Walk, trying to dodge Fanny Cornforth, a former "stunner" who was running to fat and making menacing noises about being paid off for past services. In the end clever Fanny cleared out as much art as she could carry from Cheyne Walk, and set up "The Rossetti Gallery" in Old Bond St to convert her nest egg into cash. Rossetti, meanwhile, died of kidney failure, quite possibly without his testicles, which had been plaguing him for years.

Quite properly Moyle acknowledges that her work rests on the scholarship of Jan Marsh (the Rossettis), Fiona MacCarthy (Morris) and Tim Hilton (Ruskin). For Desperate Romantics will not tell you anything about the pre-Raphaelites that you have not heard before. It will, though, remind you of how all those wild young men and marginal girls fitted together in a nexus of mutual need and exploitation which produced some of the most striking art of the 19th century. It's got television written all over it, and in a good way, too.

 Kathryn Hughes's biography of Mrs Beeton is published by Harper Perennial.