Art patron and heiress Peggy Guggenheim helped to shape the canon of 20th century art, but, says biographer Mary V. Dearborn, history has not given her her due.

		"MISTRESS OF MODERNISM: THE LIFE OF PEGGY GUGGENHEIM" By Mary V. Dearborn Houghton Mifflin ($28)

A difficult person to like, she was both extravagantly generous, financially supporting abusive friends and former husbands, and yet stingy in ridiculous little ways.

She thrived on independence but continually stumbled into dependent relationships. She was a terrible mother to her own children but doted on more than a dozen dogs, some of whom are buried with her in Venice.

Dearborn, whose subjects include Norman Mailer, Henry Miller and Louise Bryant, addresses Peggy's reputation straight on:

"The general assessment was not only that she was unimportant but that she was a fright, a predator, and finally a joke. ... Peggy was a powerful person during her five years in New York; as one of America's leading art impresarios, she could make careers. Some observers are uncomfortable with a woman wielding so much power. ... Some people are particularly threatened by erotic energy in a woman of power and influence."

The path to this position was a tortuous one and it makes a great story. Within the first few pages, Dearborn establishes her subject as both admirable and difficult and provides enough entertaining and gossipy bits to hook even a casual reader.

Peggy's father, Benjamin Guggenheim, brother to Solomon, left the family mining business and lived on his interest in the company, making his daughter one of the "poor" Guggenheims.

Born in 1898, Peggy spent an unhappy childhood in New York and settled herself in Europe as soon as she was old enough to leave home.

There she immersed herself in a bohemian crowd, marrying or living with three abusive men before finding her metier, an act that had eluded her while she was emotionally dependent on a partner.

Her first gallery, Guggenheim Jeune, opened in London in 1938 to the derision of her friends and the scorn of her uncle Solomon and his influential mistress.

The gallery flourished, however, drawing positive press notices with shows of such artists as Jean Cocteau, Wassily Kandinsky, Alexander Calder and Henry Moore.

As Peggy's own collection grew, she developed an impressive eye for art. In part, she knew who to ask for advice -- Marcel Duchamp was a trusted mentor -- and, in part, she simply knew.

Drawn as she was to art, she was also drawn to artists and writers themselves, and had affairs with Duchamp, Yves Tanguey, Samuel Becket and a marriage of several years to Max Ernst.

While these relationships varied in importance, they never subsumed her identity the way her earlier relationships did.

Her move to New York during World War II led to the opening of Art of This Century and the height of Peggy's influence on the art world.

Unlike her uncle's high-minded museum, Peggy's gallery was founded on "a democratic impulse that broke down the barriers between high art and popular culture.

This impulse was not wholly Peggy's -- she was influenced by architect Frederick Kiesler, a visionary who built curved walls and insisted that art not be framed.

Peggy's gallery was the first to show Jackson Pollock, and the list of artists who either got their start in her gallery or appeared there early in their careers includes Willem de Kooning, Clyfford Still, Mark Rothko, David Hare and Giorgio de Chirico.

Guggenheim closed the gallery in 1947 and settled in Venice, where she opened her collection to the public and showed it in the 1948 Venice Biennale, an unheard-of distinction.

She died in 1979, leaving the control of her collection to the Guggenheim Museum.

One is struck in a powerful way, in reading about Peggy's collecting, by the notion of how completely this era has vanished.

According to Dearborn, "Aggressive dealers and well-funded Olympic-sized institutions like the Guggenheim have joined forces to forge a modern art business-cum-tremendous-profit machine, building a market accessible only to affluent buyers and at the same time as rankly commercial as Disney World."

But Dearborn is not completely pessimistic. She sees evidence of Peggy's democratic spirit in such places as Andy Warhol's Factory and Keith Haring's Pop Shop, that "dissolve the boundary between high art and popular culture up to our own day. Peggy's vision of a truly vital art world may be elusive, but it survives."