One man's fun is another man's funeral

Concluding his essay "Pen, Pencil and Poison", Oscar Wilde wrote of Thomas Griffiths Wainewright (1794-1847) that "To be suggestive for fiction is to be of more importance than a fact". Wainewright was a Romantic artist and critic, and a foppish connoisseur "mincing... tremulous... his hair curled and full of unguents and his cheeks painted". He was also a forger and a murderer. By Wilde's time, Wainewright had already inspired fiction by Charles Dickens and Edward Bulwer-Lytton, and since the 19th century has provoked a handful of biographies and exercised the pens of Hal Porter and now Andrew Motion - is this enough to justify his crimes?

In brief: Wainewright exhibited at the Royal Academy and wrote flamboyant art criticism for the London Magazine during its brilliant heyday in the early 1820s. He adored Henry Fuseli, painted Byron, and had his compositions admired by Blake (to whom he reciprocated with commissions). He entranced "gentle" Charles Lamb, the peasant poet John Clare called him "a very comical sort of chap", and he was an early advocate of William Wordsworth and John Keats. Despite these brilliant prospects, however, Wainewright was obliged to forge Bank of England bonds to sponsor his ultra-sophisticated tastes in fine art and sparkling dinner parties, and when that money ran out, he seems to have taken to murder.

Following the suspicious deaths of his uncle, then his mother-in-law and most suspiciously his sister-in-law, Wainewright fled to France, but was arrested on his return to London in 1837. He was never tried for murder, but was transported for life to Van Diemen's Land for forgery. After a year mending roads he served as a hospital orderly and then achieved some sort of autonomy as one of Australasia's earliest portrait painters.

Within a decade of his death, an anonymous columnist in the Hobart Town Courier had predicted that "a famous novel" would be based on Wainewright's life, and in the following years the implication that Wainewright was a subject for fiction rather than research meant that he was mythologised as a cruelly artistic murderer, taking on the contours of sadistic and unrepentant gentlemen drawn from annals like the Newgate Calendar . This trajectory culminated in Wilde's "Pen, Pencil and Poison", in which Wainewright is figured as a connoisseur who perfected the fine art of poisoning with the same grace and genius and cool detachment as he practised his brushstrokes. Indeed Wainewright only really comes alive in the hands of Wilde, who forges Wainewright as a decadent martyr. Moreover, in doing so, Wilde was fatally anticipating the catastrophe of his own life by fulfilling his aesthetic claim that life imitates art.

And yet the skein is still more tangled, for Wainewright's own prose is a flamboyant cascade of competing characters. His voice is legion, for they are many. He signed himself "Janus Weathercock" or "Cornelius Van Vinkbooms", and also wrote a fake autobiography, Some Passages in the Life etc. of Egomet Bonmot Esq .

Motion deals with these related confusions, mythologisations and slipperinesses by writing his life of Wainewright as a pseudo-autobiography: a first-person confession or piece of creative non-fiction in the tradition of Peter Ackroyd's Last Testament of Oscar Wilde and Richard Rayner's The Blue Suit . It is spun from Wainewright's own words, contemporary accounts (for example Dickens's Great Expectations ), and "the rest is my invention". As Wainewright's own two-faced pseudonym "Janus Weathercock" puts it: "Those niceties and particularities of narration which are to be found in myself - and all other authors of value and credibility, are the tests, the witnesses, the vouchers, for the authenticity of the tale for every tale is or ought to be (after a fashion) historically true."

Motion's tactic is, then, an opportunity to tangle even further the cat's cradle of life and art, while pondering problems of character and voice. The first-person Motion-Wainewright is particularly good, for example, on the repetitive problem of the self as a hedge against nothingness, and also provides an especially elegiac passage on board the transportation vessel when an albatross is shot. The convict Wainewright reads the scene through Coleridge's Rime of the Ancient Mariner , underscoring the Wildean credo that life (even under terrific trauma) is most fully felt through the mediation of art. Interestingly, the surging imaginative power of this passage also reminds us that Motion is a fine poet of the sea - evinced in collections such as Sal****er .

But this is literally only half the story. Not content with writing one experimental biography, Motion has actually written two. Beneath the fizzing surface of Wainewright's pastiche courses an elaborate editorial commentary dealing with the inscrutability of historical evidence relating to Wainewright (commentators cannot even agree on the colour of his hair). This extended scholarly essay performs the exact opposite of the screwed-up confession by unpicking every biographical proposition and anecdote.

The power of the forked text of Wainewright the Poisoner lies therefore neither in Motion's effervescent pastiche nor in his biographical fastidiousness, but precisely in the relationship between the two texts. This is most effective in the account of the death of Helen Abercrombie (the sister-in-law). The first-person Motion-Wainewright describes the extravagant care afforded to Helen, while the extended discursive editorial note chillingly reconstructs the probable sequence of events that concluded in her being poisoned by strychnine. This elegant structural conceit allows us to glimpse between two versions of a life the character that cannot be written - in this case a masterpiece of depravity.

I swore the world which scouted me should see That I could be revenged - and terribly I kept my promise - what I've done, I've done - It might be death to some - to me 'twas fun. ( Some Passages in the Life etc. of Egomet Bonmot Esq .)

Nick Groom is lecturer in English literature, University of Exeter.