For a man who cheerfully admits his seduction by the world of wealth and class, Robert Lacey is looking decidedly casual when he meets PW at his elegant home on the fringes of London's Belgravia district. He has just returned from the gym. Wearing a grey sleeveless T-shirt, shorts and sneakers, he pads about making coffee as we chat. The house is busy. His wife Sandi, (his second), is just leaving, and his teenage son, Bruno, is round and about, dealing with the delivery of some plants. His secretary, Nina, is making notes at the kitchen table.

Belgravia is one of the city's smartest addresses, and Lacey's residence there (he also keeps a home in Palm Springs) is significant, reflecting the fact that this is a bestselling author who, from relatively humble beginnings, has proven adept at infiltrating international circles of affluence. But he doesn't stand on ceremony, taking us out into the small, leafy garden at the back of the house: more plants here, hanging over us like outlandish space age creatures.

Lacey, whose books include Majesty, Aristocrats and The Kingdom, all bestselling accounts of (respectively) the British monarchy, the British aristocracy and the oil sheiks of Saudi Arabia, projects the sangfroid of someone who has had a roving, cosmopolitan life. Despite some fierce lines in his face, he looks younger than his 54 years. But underneath the urban veneer, one senses a certain toughness. A number of those years were spent as a hard-nosed journalist on the Sunday Times.

Lacey's new book, Sotheby's: Bidding for Class, out from Little, Brown, tells the history of the British auction house from its foundation in 1744 to the present. While the book has had many good reviews in the British press, some critics found it too admiring of the privileged culture it describes. It has also rekindled the furor still lingering from a previous book on the subject, Sotheby's: The Inside Story (Random House, 1997) by Peter Watson, a former Sunday Times colleague. Watson took a more outspoken approach to the issues of illegal art export, bid rigging and other alleged sharp practice by the auction house. "I covered the issues,'' says Lacey, "but didn't feel as over-indignant about them as Peter did -- we fell out, in fact." The outcome of the Watson book was the sacking of various Sotheby's employees and a full-scale PR onslaught by Sotheby's. "They were visibly chagrined by Peter's book,'' says Lacey, "and then they had the extra burden of me watching it all -- but they were good sports."

Perhaps they will regret it: it has been said that Lacey gets too close to his sources, g s too deep into the world of glamour and power which he has made his subject. The critic Bevis Hillier, who thought Lacey "quite exceptional" when he first read his journalism in the 1970s (he ranked him with Evelyn Waugh and Martin Amis ), now apparently thinks less of him for deciding to be a rich writer rather than a revered one. "Once on the monogrammed pajama circuit, Lacey stayed there," Hillier wrote in a lively review of the new book in The Spectator.

He is being a little unfair, but only a little. Sotheby's: Bidding for Class is written in a style that veers between high seriousness and a sort of gossipy breathlessness. It includes fly-on-the-wall presentations of splashy, contemporary auctions, such as that of Jackie O's effects or Princess Diana's frocks. Lacey pens sharp portraits of significant Sotheby's figures, too, such as the mercurial Peter Wilson -- who presided over the firm's success in the 1950s and '60s and was involved in the scandal of the smuggled Sevso silver hoard ( a cache of Roman silver of questionable provenance) -- and the flamboyant Diana D. Brooks, the current chief gavel-basher. In that role, as auctioneer, her job is, he writes, "to glide between two irreconcilable illusions -- loot and hope."

The new book's theme is the way in which moneyed people through the centuries have tried to show their social standing by their purchase of art or luxury goods. Lacey's spin on this old idea is to reveal the sheer level of chicanery to which both auctioneers and bidders will go to make a sale or purchase. He is quite honest about his own motives in this regard. "I've only ever written for money, you know," he says, leaning back in his chair with a rascally grin.

"It's true, I'm fascinated by elite groups," he g s on. Sotheby's, which uses class-consciousness and the British heritage experience to sell artifacts, taking advantage of national snobbery, thus presented a perfect subject. "It seems to me that Sotheby's is very much like the British monarchy: an old and apparently very venerable institution which is in fact very nimble on its feet, an institution invested with a great deal more self-interest than the public image would suggest.''

Lacey himself suggests a personal angle to the story. "My whole life as a grammar-school boy, getting to Cambridge University and working on the London Sunday Times has been very aspirational.'' Born in Surrey in 1944, he had middle-class roots (his father was a banker). After winning a prize in a short-story competition, he wangled jobs in journalism, first on the Illustrated London News and then on the Sunday Times under Harold Evans. Lacey worked on the paper's famous "Insight'' investigative team, and says that his books bear the stamp of that experience: "You know, the in-depth research for months and months, the anecdote at the beginning which sets the scene and takes you into the event, how you dramatize the story as much as you can but never make it up, invent a source, or do a composite... all those sorts of things.''

By the early 1970s, Lacey was pursuing his own writing at home, before and after work. He produced a number of respected books on historical figures, writing Robert: Earl of Essex (1971) when he was just 27. The Life and Times of Henry VIII and Sir Walter Raleigh soon followed, but Lacey became restless. The books were serious, well-published traditional biographies-but not bestsellers. Animatedly, he explains how his evolution to bestselling chronicler of the rich and famous took place. "So there I was, working in the newspaper all day and doing research and writing first thing in the morning and at night. And then my wife said, 'it's great getting these marvelous reviews but the books don't sell, and the family never sees you, so can't we come up with something that would sell?' And that was how the idea of Majesty was born.''

Inside the Monarchy

Majesty: Elizabeth II and the House of Windsor, was Lacey's first big book and a testament to his skill in searching out subjects of immense popular interest. Published in 1977 by Hutchinson in the U.K. and by Harcourt Brace in the U.S., it was number one in Britain for five months. It is now widely seen as being a prime mover in the royal-books market that has grown so much in the last two decades. "The idea about Majesty was that I would take a look at the monarchy as an outsider, independently, and write about it in an intelligent, analytical way,'' says Lacey. "We are quite familiar with this now, but at the time it was the first.''

After Majesty came The Kingdom (published in the U.S. by Avon, 1981), Princess (Times Books, 1982) and Aristocrats (BBC/Hutchinson, 1983). All of these, by Lacey's own admission, were attempts to resist publishers' suggestions that he write "Son of Majesty'' -- a book about Prince Charles. With Majesty, he says, the process of getting close to his source became part of his modus operandi. "It was through Lord Mountbatten that I managed to get into the Royal Family. I wrote to him and he said 'come and see me' and agreed to help. He asked to see what I wrote and I was very uncomfortable about this as a journalist, you know -- but what was the choice? In fact, I discovered that this was a very useful technique, as an informant will write back to you with lots more suggestions. Seeing your work sparks off their memories, you get a lot more material and you win their trust.''

For The Kingdom, the story of Saudi Arabia, getting close to the source proved far more difficult. Having left the Times in 1974, Lacey moved to the oil-rich desert country with his family, using the money from Majesty to support himself. "It was a very expensive enterprise and took five years, and it was a tremendous upheaval for the family.'' Even at the outset, getting a visa as a writer proved difficult. Then he had to learn Arabic. Informants were cagey, and everyday life in Saudi Arabia was oppressive. So why did he write it? Partly romance, and partly money. "Living in the '70s, with gasoline queues and so on, one was aware of the importance of the oil sheikhs, but what grabbed me was a marvellous story Gita Mehta, Sonny Mehta's wife, told me one night, the story of Ibn Saud, the first Saudi king, how this boy living in exile in the desert went from oasis to oasis unifying the country and calling it after himself, and then out of the ground comes oil, like a wonderful benediction.''

Despite strong U.K. sales, The Kingdom still failed to crack what Lacey considered the promised land -- the U.S. market. Casting around for a new subject, he met Bill Phillips at Little, Brown through his agent, the late John Cushman, "I hit it off with Bill," Lacey recalls, "and he suggested a book on the Fords to me. He'd actually been down to the library to check it out and discovered that there hadn't been a book on the Fords since the 1950s.'' This was the genesis of Ford: The Men and the Machines (Little, Brown, 1986), Lacey's bestselling book so far, with around 115,000 copies in hardback in the U.S. Translated into 10 languages, it made Lacey well over a million dollars.

As with The Kingdom, deep research was seen to be the key. "Bill said, 'we'll pay for you to come over and live in Detroit.' So I did, the whole family moving lock, stock and barrel.'' While he concedes that moving to Saudi Arabia was tough on the family, but has nothing but good things to say about Detroit. It was living there, he says, that Americanized him -- his contracts are all with Little, Brown U.S., though he does confer with the head of the U.K. branch, Phillipa Harrison, who was his editor at Hutchinson for Majesty.

Following Little, Brown's publication of Little Man: Meyer Lansky and the Gangster Life in 1991, which he acknowledges to have been a commercial failure that "hopelessly underearned a large advance,'' Lacey wrote a biography of Princess Grace of Monaco for Putnam. But he returned to Bill Phillips at Little, Brown for the Sotheby's book. "In publishing terms, I feel I'm back home where I belong, on both sides of the Atlantic.''

As the arrival of new plants begins to get in the way, we decamp to the sitting room, where more fine furniture is on display. Lacey might soon be able to add more pieces-the Sotheby's book has done well in Britain. The sales please him (it has made the Sunday Times bestseller list), not least because he's now running Cover magazine, a venture that eats money. Co-edited by Danny Danziger, it is a glossy monthly that gathers up the best of journalism worldwide and repackages it.

Lacey's next book, co-written with Danziger, is Life in the Year 1000, for which the two writers have interviewed leading academics about what life was really like at the turn of the previous millennium. After that, Lacey is setting to work on Majesty: the Sequel, having finally decided that the time is right, following the recent change in British public opinion of the Royal Family.

He plans to use the same working methods he has adopted for all his books since the previous Majesty. "I will do six to nine months of pure research, for which I set myself a deadline when I've signed the advance. Then I start writing, by which I mean dictating, to a secretary. It's a technique I learned from Barbara Cartland -- just speaking it gives it a rhythm, and whatever fluency my writing has comes from that, I think.''

Lacey is a fluent writer. On that level, the success of his books is well-deserved. Like Sotheby's punters, Lacey bids for class. And he delivers it -- with some sophistication and an appropriate scent of filthy, but delicious, lucre. What he says of his latest effort could equally be said of him. "It would be great if some of the magic of the auction process has rubbed off on the book. I hope it has."