'The Victorian tree," the antiquarian and ghost-story writer M R James once declared, "cannot but be expected to produce Victorian fruit." In making this point, James - who lived almost exactly half his life within the Victorian age and half outside it - was simply acknowledging his own cultural upbringing. In fact the Victorian tree has gone on producing bumper crops with a vigour that would have surprised even Mr Gladstone. More than a century after the Widow of Windsor's death, in the 64th year of her reign, we are still clustered on the margins of her curiously elongated shadow. Here am I, for example, a hip young fortysomething, raised in the era of Sergeant Pepper and the Three Day Week, reaching out to embrace the tumult of the 21st century, and yet my grandfather, whose picture sits in the frame in my parents' dining room, fought in the Boer War.
Viewed from the angle of the family album, consequently, the Victorian age turns suddenly sharp, hard and tangible. The people in it might sport billycock hats, carry parasols and wear impractical-looking dresses, but they are connected to us, if only by dint of appearing in photographs, in a way that the subjects of a Gainsborough portrait are not. Simultaneously, the world they inhabit is intriguingly remote, full of bright, exotic images: Gordon at Khartoum, Prince Albert's whiskers, the glass dome of the Crystal Palace exhibition, the line at Balaclava. However familiar you happen to be with the seamier side of 19th-century life, the statistics for child prostitution and the incidence of venereal disease, it is impossible to drag open the door to the Victorian closet without a gust of Romanticism surging out: a kind of compound made up of fog-bound streets and gas-light, steam trains and Hansom cabs, tubercular faces and high, cracked voices echoing from attics where the sun never penetrates.
It would be odd if this view of the age of Darwin, Florence Nightingale and Herbert Spencer weren't inextricably bound up in, if not actually created by, the Victorian novel. What is it that even now that gives Victorian fiction its tremendous psychological heft? Why is it that I would far rather sit down to a re-read of George Gissing's Born in Exile or Arthur Morrison's Tales of Mean Streets than the latest Salman Rushdie? Part of this is down to the immense solidity of character than Victorian novelists manage to bring to their cast, the sense of real people, rather than social constructs or representatives of a particular aesthetic theory busily at large in a world that, to quote Melville on Trollope, looks like a slice of England placed under glass, people - more to the point - who are confident of the foundations on which their lives are built. When writers stopped believing in God, their characters lost a dimension, became the "people in paper houses" of Graham Greene's essay on Mauriac, and no amount of post-modern trickery or stream-of-consciousness mongering has ever brought this environmental tethering back.
The other great enticement of a novel like Vanity Fair or Dombey and Son - published side by side in the late 1840s - is the sense of a society in flux, a world taking shape almost too rapidly for the writers who are monitoring its convulsions to keep up. Dickens' career, for instance, began in the era of the stage coach and ended in the age of the locomotive, taking in everything from parliamentary reform and scientific revolution along the way. Socially, his and Thackeray's novels take place half-way up a metaphorical ant-heap, whose inhabitants are scurrying to make their way through a society where most of the barriers that previously worked against social advancement have either been removed or fallen away. Suddenly the world is fall of "bran-new people", to use Dickens' description of the ghastly Veneerings in Our Mutual Friend, and the fictional consequences have been with us for a century and a half.
Dimly visible beneath the ebb and flow of the average Victorian novel is a second, buried world whose representatives are occasionally let out into the first world with devastating results. Television dramatists who adapt Victorian classics for the small screen occasionally pronounce that it is their duty to lob in various bits of sex and seediness on the grounds that George Eliot, Thackeray and co would have done so themselves had they not been constrained by the Victorian censors. In fact most Victorian novelists were perfectly capable of writing convincingly about sex, whether the subject is the Marquis of Steyne's assignations in Vanity Fair or the male prostitute who wanders into Trollope's The Prime Minister. Anyone who wants a brisk demonstration of what a Victorian novelist could do with sexual passion should start with the scene in Trollope's Phineas Finn where Lord Chiltern greets the news that Violet Effingham is prepared to marry him with a cry of "My God! She is my own!" while bounding across the carpet with such bull-like eagerness that Violet is half-terrified by the emotions she has aroused.
All this is clearly prime operational territory for the novelist who follows a century or so in its wake. But having decided that you want to write a Victorian novel, how do you set about it? Immediately a host of procedural dilemmas snap into place, like a row of paperclips obeying the magnet's call. In the realm of dialogue, do you go for mid-19th-century pastiche, or do you come over all contemporary-anachronistic and have Palmerston-era roustabouts bidding their drinking chums "back to my place"? In the matter of sex, do you opt for the "shocking exposés of Victorian sexuality" so beloved of the blurb writers, or do you stop things at the bedroom door (or, as the Victorian themselves did, several storeys beneath)? Do you ornament each scene with the fruits of your research, anatomising the poor sanitation and the crawling bacilli that give the servant girl her pallor, or assume the scenery is already in place in the reader's mind?
The novelist, just as much as the historian or the small-screen adaptor, has a duty to see past life and the people who populate it on their own terms. One of the most irritating novels I ever read was The French Lieutenant's Woman (1969), the late John Fowles's account of an 1860s courtship. Not only has Fowles done his research among the mid-Victorian fashion catalogues, so that even the hat of a soliciting prostitute is immediately described in relation to contemporary styles, but he patronises his creations, takes them out into the brightly lit, book-lined study of his imagination, where Freud and Sartre stare from the walls, and condescends to them. What begins as an examination of Victorian sexual life ends up as an account of our own attitudes to that life, which is a rather different, and a less satisfactory, thing.
The plot of my novel Kept, whose half-mad heroine lies concealed in a remote country house while guardian and lawyer plot to defraud her, was suggested by the story of Thackeray's wife, Isabella, who lost her reason after the birth of her third child, tried to drown herself during a boat-trip across the Irish Channel, and spent the remaining 53 years of her life in a state of semi-autism. Without ever knowing it, Isabella inaugurated the whole "madwoman in the attic" tradition of Victorian literature. When Charlotte Brontë dedicated the second edition of Jane Eyre to Thackeray, a rumour sped round literary London to the effect that the novel was a roman à clef, with the author as the heroine, Thackeray as Mr Rochester and Isabella the wild-eyed dement upstairs.
Kept is also a kind of homage to the "voices" of Victorian literature that have haunted me ever since I started reading Victorian novels: George Moore's servant girl, Esther Waters, as she stands on the station platform at the start of her new life; Mary Mann's Norfolk labourers; Trollope's conniving lawyers. One of the oddest voices I ever came across, and borrowed for my own heroine, is that of Thackeray's eldest daughter Anny, as revealed in the journal she began shortly after her father's death in 1863. She was confident about certain things, timorous about others, near-masochistic about her failings and "unworthiness", practically sexual in the intensity of her feelings for her lost papa - her journal is a quintessentially Victorian document. The point about Anny Thackeray is that, in the last resort, she is not like us, not there to be taken out and used - which is what nearly all history does - as a way of demonstrating our superiority to the people who preceded us in time. Like everyone else, the Victorians deserve lives of their own.
'Kept' is published by Chatto (£16.99). To buy a copy for £15.50 (free p&p), contact Independent Books Direct on 08700 798 897 or post your order to PO Box 60, Helston TR13 0TPReuse content