High prices are everywhere in this city, from real estate to restaurants. While most Americans may be daunted by the weak dollar, the international rich, aided by tax advantages, aren’t deterred. On the contrary, they are clamoring for homes here, and shoppers speaking Italian, French, Japanese or Russian are crowding the stores. It is not surprising, then, that the annual June art auctions, which ended on Friday, have made London a more important art capital than it has been for more than 20 years.Even the pros were surprised. “It’s unbelievable,” Edward Dolman, chief executive of Christie’s, said on Friday. “A few years ago if you had told me that we’d sell about $450 million worth of art here in a week, I would have said you’re joking. For the first time we’re seeing American consignors asking to sell their art here.” For more than two decades London has taken a back seat to New York. Sales here were considerably smaller, and buyers tended to spend less money. Although this season there has not been a painting that has brought more than $70 million, as there was in New York last month, the London sales were not only filled with more important works of art than ever before, but more buyers were also willing to pay almost anything for a painting, drawing or sculpture by a brand-name artist. While the weak dollar has made it attractive for Americans to sell in London, perhaps the biggest difference is the amount of new wealth from denizens of the former Soviet Union. Russians and Ukrainians — some living in Geneva, others in London — have jumped into the auction game, pushing prices to record levels. “These new guys have completely transformed the market,” Mr. Dolman said. “They live in Europe and come to view the art here. They don’t necessarily come to New York. Although some will bid by telephone at the New York auctions, it’s not the same.” One mysterious, dark-haired man in particular could be seen buying or bidding on everything from paintings by Matisse and Miro to David Hockney and Frank Stella. Shy of the press, he has delighted in inventing different names to confuse journalists who ask him who he is. Auction house officials, however, have identified him as Ghar Ivanishvili, a nephew of the Georgian mining magnate Boris Ivanishvili, who is said to be building a museum in Kiev. (Boris Ivanishvili is believed to be the anonymous buyer who spent $95.2 million for Picasso’s “Dora Maar With Cat,” at Sotheby’s in New York in May 2006, although the unidentified man who was bidding on his behalf at the New York sale was an employee. The nephew, however, did buy “White Canoe,” a 1991 painting by the Scottish artist Peter Doig for $11.2 million, five times what it was estimated to fetch and a record price for the artist, when it was sold at Sotheby’s during the auctions here in February.) Ghar Ivanishvili wasn’t the only big spender this week. At Christie’s sale of Impressionist and modern art on Monday night two telephone bidders, who dealers and auction house experts speculated were Russian collectors living in Geneva, bought about 30 percent of the works.Although European buyers dominated — the auction houses include Russians in that category — Asians and Americans bought some high-priced art too. At Christie’s sale of Impressionist and modern art, a telephone bidder described by the auction house as an American collector, bought the most expensive painting in the sale, paying $35.5 million for Monet’s “Waterloo Bridge, in Fog,” a dreamy landscape from 1904. (In 1990 the painting sold for $3.4 million at auction at Sotheby’s New York.) It wasn’t the only high price paid for Monet last week. At Sotheby’s the next night an auction-house representative from Hong Kong took the winning bid from a telephone buyer for one of this artist’s famous images of waterlilies, also painted in 1904. Five bidders went for the painting of the lily pond in Monet’s garden at Giverny, France; it fetched $36.7 million, far more than its high $30 million estimate. (Final prices include the auction houses’ commission: 20 percent of the first $500,000 and 12 percent of the rest. Estimates do not reflect commissions.) As has been true for several years now, popular taste gravitates toward postwar and contemporary art. This city is teeming with contemporary art galleries, and most of them had special exhibitions timed to the auctions. One, White Cube Gallery, is getting the most attention as people line up to see Damien Hirst’s $100 million, platinum skull set with 8,601 diamonds. (It was still unsold as of Friday.) Mr. Hirst grabbed the limelight at the auctions too. At Sotheby’s on Thursday night he became the most expensive living artist at auction when “Lullaby Spring,” a 2002 stainless-steel cabinet filled with 6,136 painted, bronze cast pills, was sold to an unidentified telephone bidder for $19.2 million. Frank Dunphy, Mr. Hirst’s business manager was there, reporting to him by cellphone. “Damien was blown away by the price,” said Mr. Dunphy, who would not identify the buyer. “We were betting it would go for $10 million to $20 million.” Just 24 hours earlier Lucian Freud had the honor of being the most expensive living artist ever sold at auction. On Wednesday night at Christie’s, a 1992 portrait of Bruce Bernard, a British photo editor who died in 2000, sold for $15.6 million. David Dawson, Mr. Freud’s longtime studio assistant and model, could be seen standing in the doorway of the sales room, also reporting on the auction from a cellphone. Once the painting was sold, he quietly slipped out. Neither the cabinet by Mr. Hirst nor the painting by Mr. Freud was the most expensive contemporary artwork sold last week. That honor went to Francis Bacon, whose 1978 self-portrait brought $43 million. Anthony Grant, a specialist in the contemporary art department at Sotheby’s in New York, took the winning bid. After the sale dealers said they thought the buyer was Stefan Edlis, the Chicago collector who recently sold Warhol’s “Turquoise Marilyn,” to the hedge-fund billionaire Steven A. Cohen for $80 million. Tobias Meyer, director of Sotheby’s contemporary art worldwide, said the Hirst and the Bacon “sit outside the market because they can’t be replaced.” Christie’s sales consistently brought higher totals than its archrival, Sotheby’s. Christie’s Impressionist and modern art auction reached $239.9 million, compared with Sotheby’s $159.5 million; Christie’s postwar and contemporary art drew $147.2 million, while Sotheby’s totaled $144.3 million. Throughout the week the work of Chinese contemporary artists, who have been all the rage for the last two years, continued to bring high prices. Phillips de Pury & Company, the boutique firm, even held its own 38-lot sale of Chinese contemporary art on Friday afternoon, immediately after its general contemporary art auction, where several artists, including Zeng Fanzhi, Cao Yong and Gu Dexin, brought record prices. The second session also saw record prices, and the two sales combined — filled primarily with works by younger artists, whose prices are cheaper than those of blue-chip artists — totaled $46.5 million. That was the company’s highest ever for contemporary art, outstripping its New York sale in May. “We saw an influx of new buyers from Eastern Europe and Asia,” said Michael McGinnis, worldwide director of Phillips contemporary art department. “For us it was really a home run.”