To make his mark in the art world in the early decades of the 20th century, dealer Joseph Duveen broke from convention.

One of his first rules was to buy high and sell higher. If it was a bargain, the work probably wasn't worth owning in the first place, he figured.

His other rule limited his risk. He'd line up a buyer before he'd make a bid. By offering the highest price, he'd usually walk away with the prize and still pocket a profit.

Since he often bought collections of work, sales of single pieces brought in far more than what he paid for the lot.

Duveen's strategy helped make him the most successful art dealer of his time. And he was a key factor in the steep appreciation in price of British paintings and Italian old masters — his specialties.

Many of his customers eventually donated works to emerging American museums, such as the National Gallery of Art, the Frick and the Detroit Institute of Arts.

Duveen (1869-1939) operated on the premise that "Europe had plenty of art, and America had plenty of money," wrote one biographer, S.N. Behrman.

It helped that Duveen sold only work he loved and admired. His enthusiasm was contagious. He made avid buyers of American business tycoons such as J.P. Morgan, Andrew Mellon, Benjamin Altman and Samuel Kress. The new American money desired the old European masters, and British-born Duveen was happy to oblige.

Ready The Sell

According to Meryle Secrest's 2004 biography, "Duveen: A Life in Art," he once said: "I don't have any more of a gift for selling than anyone else, but it's that I truly believe in the work I want to sell. It is my inner confidence that makes me eloquent."

Preparation was key. He'd research the work's history — who painted it and when, plus the trail of collectors who bought it. To gain a head start on rivals, he'd look for work before it went on sale and hire scouts to connect with European collectors and owners of the great country estates of Britain.

A global grain glut starting in the late 19th century and lasting for decades struck the British aristocracy hard since they relied on rents from their farm land. To keep the big estates going, they started selling off centuries-old paintings and sculptures. Enter Duveen.

"(Duveen) had perfected the art to which every dealer aspired, that is, to know where all the great paintings were," Secrest wrote.

Because the art market was riddled with copies, Duveen went to great lengths to authenticate the work. He hired experts and got second and even third opinions.

Duveen schooled himself in the British master painters, but he was out of his depth when it came to old Italian masters. So he hired Bernard Berenson, an expert in the field, and gave him a stake in the profit.

Duveen also tried to learn all he could about potential buyers. Since many were leading American business and political figures, he read up on economic and political issues.

He scanned newspapers to find out when they were due in court, set to sail across the Atlantic or to celebrate a birthday. He'd sometimes book passage on the same ship in order to introduce himself.

He wrote them notes, sent them gifts, got them party invitations and good seats at sold-out plays.

He cultivated critics, museum directors, restorers, architects and decorators in the same way. Deck stewards and other servants sent him leads on buyers he wanted to court — for a fee.

Duveen tracked Kress, a dime-store magnate, for years before he finally cornered him in New York in 1933. Knowing that Kress liked to buy in bulk, Duveen showed him paintings that included Duccio's stunning "The Calling of the Apostles Peter and Andrew."

Kress — who had been buying art from another dealer — was a hard bargainer. Duveen sold him the Duccio and two lesser works at a loss. But as Secrest pointed out, Duveen had "reeled him in" and gradually sold Kress other works for a handsome profit.

To entice Mellon to buy paintings, tapestries and other art objects, Duveen put those objects in a furnished apartment he rented right under Mellon's in Washington, D.C. Then he invited Mellon to visit any time. Mellon did visit — then began to hold receptions there.

Mellon went on to buy nearly the entire contents of the apartment. The purchase price in 1936: $21 million, a record-high sale for Duveen.

"Duveen was always ahead because he had no other life. . . . Other interests were subservient to the one compelling interest of his life," Secrest wrote.

As a youngster, Duveen often accompanied his father on buying trips. His dad's antique business specialized in porcelains, tapestries, rugs and furniture. Joseph started working in the business wrapping items and building packing cases. Gradually he attended the big auctions in Paris.

Duveen's father, Joel Duveen, a Dutch merchant of Jewish ancestry,had moved to London, where he built a following that included English royals such as the Duke of York and Edward VII.

Joseph, his oldest son, was more interested in paintings than tapestries and furniture. He wanted the family business to deal in Raphael, Titian, Turner and Gainsborough.

His father was dubious. He knew that the high-end art market was a tough business. Italian Renaissance works were hard to find, often damaged, and purported originals were sometimes copies.

The young Duveen persisted, and his father finally agreed. Duveen later took control of the business, buying his brothers out.

To gain the trust of buyers, Duveen learned from his father to offer to take back the work if the buyer wasn't satisfied. The guarantee usually worked well, but sometimes it backfired.

Benjamin Altman, a department store magnate, returned a Velazquez painting of the Count-Duke of Olivares after hearing that a similar full-length portrait of the Duke had been sold to another collector.

To reduce the risk of dealing in fakes, Duveen often went after the most prominent collections. By offering prices higher than anyone else, he was able to score two major coups early on. One — for $4.2 million — was the Rodolphe Kann collection, with its Vermeers and Van Dycks. The other was the Oscar Hainauer collection, which included work by Rembrandt and other Dutch and Flemish masters.

Paid Off

Duveen's investments, often financed by banks and other loans, were quickly recouped, and then some. For the Kann collection, "secret sales were made even before the collection was officially bought," Secrest wrote.

Though he made millions buying and selling, Duveen also viewed his work as a mission. To educate British people about art, he organized exhibitions. To lure buyers, he had catalogues printed with prices listed. He included many young, unknown modern painters.

In 1915, Duveen funded four modern foreign galleries and a room for the American artist John Singer Sargent at the Tate in London.

Honored by the Royal Court in 1933 as a "peer of the realm," Duveen chose the title Baron Duveen of Millbank, an area in London where the Tate is located.

BY MARILYN ALVA