IN THE CAPRICIOUS WORLD of high fashion, there are two types of collectors: those who treat their acquisitions with white-glove care, cataloguing their inventory inside temperature-controlled shrines; and those who rip off the price tags, wear the hell out of their garments and then shove them back in their closets. Unsurprisingly, each views the other as deeply foolish.

Anna Piaggi, the late Italian fashion idol and longtime contributor to Italian Vogue, was the ultimatespontaneous and undisciplined fashion worshipper.

Until her death at age 81 last August, Piaggi lived with a vast collection of clothing in a dark and cluttered Milan apartment, where she continually begged her landlord to rent her extra rooms to accommodate an ever-expanding sartorial inventory. By the end of her life, 40 rolling racks had overtaken every wall in every room, where priceless pieces by Poiret from 1912 tangled with modern-day Dior and McDonald's staff uniforms. This supremely stocked closet was the source of the riotous outfits Piaggi created every morning, offsetting layers of valuablehistorical costumes, contemporary haute couture and worthless dime-store finds with her waves of dyed-blue hair, cupid-bow lips and powdered-white face.

'She was not a fashion curator,' says designer Karl Lagerfeld, who first met Piaggi in the early '70s. 'She lived with her clothes, old and new, and never paid attention to them in a special way. They were part of her daily life.'

Piaggi died of a heart attack while watching TV at home alone. She was scheduled to finalize her pages for Italian Vogue's October 2012 issue the following morning, but she never made it to the meeting. With no children of her own, her clothes and accessories were passed on to her brother, Alberto. Overwhelmed by the size and significance of their inheritance, he and his son, Stefano, called Judith Clark, professor of fashion and museology at London's University of the Arts, who had collaborated with Piaggi on a popular exhibition dedicated to her style at London's Victoria and Albert Museum in 2006. 'We met down in the basement of her apartment building to see the clothes she had never shown anyone,' Clark recalls of meeting Alberto and Stefano after Piaggi's funeral. 'They were in one of the worst states of conservation I've ever seen, but at the same time, [her collection] was full of historic gems.'

Piaggi's estate also piqued the interest of Milan's former cultural assessor, Stefano Boeri, who wanted to lay the foundation for the city's first fashion museum using the clothes. Alberto put Clark in touch with Boeri and together they began talking about creating a professional database for each piece, hoping to find a permanent home for them at Milan's Fabbrica del Vapore. But in March, Boeri was fired, and the plan disintegrated.

The collection now hangs untouched in her brother's storage space, its future uncertain.

DESPITE HER VERY LOUD LOOKS, Piaggi was a quiet woman. 'She was very discreet,' says Italian Vogue's editor in chief, Franca Sozzani, who worked with Piaggi for 23 years. 'I never knew anything about her personal life.'

Born in Milan in 1931, Piaggi was inducted into the fashion world by the photographer Alfa Castaldi, to whom she was married until his death in 1995, and with whom she collaborated on Arianna-one of Italy's first women's magazines-and the avant-garde publication Vanity. But her style compass was set by vintage dealer Vern Lambert, a longtime friend who introduced her not only to the allure of old clothes but to Karl Lagerfeld. (Her relationship with him was recorded in Karl Lagerfeld: A Fashion Journal, a book published in 1986 of his many sketches of Piaggi and her clothes.)

'The period after Vern Lambert died [in 1992] started to be a sadder period of her life,' remarks Lagerfeld, who fell out with Piaggi around the same time. But even so, Piaggi continued to enthusiasticallychampion designers, acting as both muse and client to young names like Gareth Pugh and established talents such as Manolo Blahnik, who famously called her 'the only authority on frocks left in the world.' Another of her closest relationships was with milliner Stephen Jones-beginning in the '80s, she capped off every one of her looks with a hat bursting with anything from fruit and fur to a warped clock and dead pigeons.

Though she spent nearly a half century contributing to Italian Vogue, where her doppie pagine-double-page spreads of collages of text and images-revealed esoteric cultural references and an academic knowledge of fashion, Piaggi was best known for how she got dressed in the morning.

Whether it was for a lightbulb-flooded front-row seat along a runway, or a banal trip to the butcher (where she once ordered a slab of beef in 15th-century Milanese chain-mail regalia), her outfits were laborious constructions of fashion theater. 'My philosophy of fashion is humor, jokes and games,' she told WWD in 1978. 'I make my own rules.' She wore giant Union Jack capes with 19th-century pantaloons; nurses' uniforms with Manolo Blahnik boots; and dresses whose 'page layers' made her look like a walking novel.

Some might say Piaggi was a precursor to the conspicuously costumed bloggers, editors and aspiring glitterati who now populate fashion shows, hoping their pictures will end up online. But Sozzani disagrees. 'You can't even compare the two-those people are sponsored by brands, and it's more like watching shop windows,' she says. 'Anna never wore something because it was the latest skirt or newest shoe. She experimented with fashion on herself and liked to have a story for each object she was wearing.'

Those stories were about '20s Chanel dresses, costumes from the Ballets Russes and an entire wardrobe created in the 1870s for a Roman princess by Charles Frederick Worth (the world's very first haute couture designer), bought for her by Lagerfeld. But even with highlights such as these to give shape to her closet, its full extent remains a mystery. 'Anna was the only one who had access to the clothes and who understood where everything was,' says Moreno Fardin, Piaggi's assistant of 16 years. 'Every once in a while she'd call me in to help her move a rack and then discover something-like the beautiful [Pierre] Cardin she got married in. She never archived anything.'

For the 2006 Victoria and Albert exhibition, Piaggi provided the museum with a list of her wardrobe's contents: 265 pairs of shoes, 932 hats, 2,865 dresses, 1 exercise bike and 31 feather boas. 'I am rather certain Anna made all of that up,' says Clark. 'She didn't have a clue as to what was in her closet.'

When it came to getting dressed, Piaggi's intimacy with her clothes came quite literally at a price. 'When you wear the dress, you also wear it out,' says Pat Frost, director of textiles and costumes at Christie's. 'Its value goes down, and it is much less likely it will end up in a museum.' Conversely, in perfect condition, high-end couture can yield big results. A '30s design from Vionnet, according to Frost, can fetch over $75,000, while Christie's sold a Schiaparelli jacket for nearly $100,000 last November.

In 2009, when Christie's auctioned a small portion of Piaggi's best historical pieces, the 17 garments in the lot yielded an unspectacular $51,867. 'The only truly successful item was a Jean Paul Gaultier cone dress [sold for $20,000],' says Rome-based fashion historian and curator Enrico Quinto. 'This is a woman who used to use a Fortuny dress as a scarf. She was cutting and customizing her pieces. Anna desanctified the clothing. She deconsecrated it.'

What now lays in storage is an assemblage of garments that reflects a full life. 'The collection is more interesting as a whole rather than in single pieces,' says Clark. 'It's an accumulation of her looks and moods and how she wanted to dress up that day.' But what's to be done with a collection that gives equal weight to Juicy Couture as Dior Couture? Alberto and Stefano Piaggi are hoping to organize a series of exhibits in Milan, 'and maybe even a fashion show of her clothes,' says her brother. 'I don't think Anna would've liked to have been in a big museum.'