It was William Beckford's misfortune to have been born too rich and then to live too long. For anyone else, these circumstances need not have become drawbacks but, as a proto-Romantic, Beckford enjoyed more affluence and longevity than was beneficial; an altogether briefer and more impoverished existence would have been better for both his creative output and posthumous reputation. Having, as he felt, suffered unjustly at the hands of his contemporaries - very romantic, that sense of aggrievement - Beckford was especially concerned with how he might be perceived by subsequent generations. Before his death, therefore, he took a great deal of trouble to make sure only the most favourable documentation would survive. Thanks to this elaborate manipulation of material, until now he has been treated with great kindness by biographers. Timothy Mowl, however, takes a distinctly rough-handed approach, denouncing Beckford in his very first paragraph as "a fluent and seductive liar who had ample funds to pay secretaries to rewrite letters and ample time in an eighty-four-year life span to reconstruct the past". Among the evidence brought in to support his case, Mowl quotes Beckford's claim to have written - at the age of six - the air "Non piu andrai" from Le Nozze di Figaro when the eight-year-old Mozart was giving him music lessons. Ludicrous as this may now seem, the story gained a certain currency even while its perpetrator was still alive. As a fantasist, Beckford was no worse than other 18th-century fraudsters such as James Macpherson who wrote and published poems widely attributed to a Gaelic bard called Ossian. Then there was Thomas Chatterton, author of a set of verses which, prior to his suicide at the age of just seventeen, he claimed came from the hand of a 15th-century priest. Both instances demonstrate a passionate fondness for the gothic which was shared by Beckford; his own fantasy story, Vathek, although originally written in French, was first published in English as "An Arabian Tale from an Unpublished Manuscript with Notes Critical and Explanatory". The complications involved in its eventual appearance were also typical of the author whose life may be read as a succession of self-inflicted disasters.

Aside from Vathek, Beckford's most famous creation was Fonthill Abbey, a vast pseudo-mediaeval construction which collapsed shortly after its sale in 1822 to a gunpowder merchant. Fonthill is often proposed as starting the gothic-revival trend, even though Horace Walpole's home, Stawberry Hill, predates it by several decades. More accurately, the interior of Fonthill serves as an early example of the 19th-century fondness for clutter; as Mowl says, Beckford's taste for gothic was "more theatrical than scholarly" and as a collector he was hopelessly indiscriminate, mixing outstanding pieces of boulle with fake-Jacobean furniture. Although he was pursued by scandal and - despite his great wealth - the persistent threat of financial ruin, Beckford's history cannot fail to fascinate and Timothy Mowl is just the latest in a line of biographers stretching back over more than a century. While he takes a franker approach than his predecessors, he fails to place Beckford in the context that matters most, namely, as the first representative of the bourgeois nouveau riche. Aristocratic airs aside, the Beckford wealth came from trade, namely sugar cane and slavery. In what has since become a familiar pattern, riches built up over several generations were dispersed in just one thanks to profligacy and self-indulgence. The richest heir in England believed himself a creature of the greatest refinement who ought not to be sullied by work and spent much of his time in unproductive dreaming. In this century, Ronald Firbank, Stephen Tennant and, especially, the English patron of surrealism, Edward James, could all be considered latter-day William Beckfords. His successors have been all those other spoiled offspring of the very wealthy who imagine themselves better than their industrious ancestors.

Robert O'Byrne is an Irish Times columnist