Who

Fashion heir Andrew Rosen is the president of Theory and an investor in a handful of fashion upstarts.

Backstory

Andrew is the third generation of Rosens to lord over the fashion trade: His grandfather, Arthur, founded the Puritan Fashions Corporation in 1910 and later handed the company over to Carl Rosen, Andrew's father, who became one of the most distinctive figures in the garment business in the '70s as the original licensee for Calvin Klein Jeans.

Andrew didn't initially plan to take over his father's business. A University of Miami dropout, he was perfecting his golf swing and coasting on the company payroll when his father summoned him to the office and told him to prepare to take over. Carl, it turned out, was suffering from terminal cancer and when he passed away in 1983, a 26-year-old Rosen was appointed his successor. Calvin Klein and his business partner Barry Schwartz bought out Puritan Fashions a year later for $100 million. Andrew stayed on as president of Calvin Klein Sport before parting ways with the company to join Anne Klein as president and chief operating officer.

In 1997, Rosen partnered with Elie Tahari to found Theory. Over the next few years, the duo built the brand's popularity with easy-to-wear neutrals, mix-and-match suit pieces, and stretch pants, attracting a cult-like following. (And they managed to do it without relying on celebrity endorsements, catalogs or fashion shows.) They cashed out of the company in 2003, selling Theory to the Japanese firm Link International for $102 million. Rosen stayed on following the sale and now heads up Link Theory Holdings in the U.S., which gives him oversight of Theory as well as the other brands in the Link portfolio like Uniqlo and Helmut Lang.

Of note

Theory is now a major force in the retail world—it generates more than $500 million in revenue a year—and has been in expansion mode. Outerwear, accessories and men's lines have all been added to the mix, and scents and beauty products are coming to stores soon. (Theory's stretch pants, however, remain the bestselling item.) New stores are in the works, too: Although the brand has long been sold by Bergdorf's, Neiman Marcus and Bloomingdale's, there are 18 Theory stores in the U.S. and Europe, including a 60,000-square-foot New York flagship on Gansevoort Street, which opened in November 2006. In his position as president of Link, Rosen has a handful of other brands to worry about as well. In recent months he's been very involved with the re-launch of Helmut Lang, which is now designed by Michael and Nicole Colovos.

Drama

In 2006, Tahari sued Rosen and Link for $182 million, claiming he pressured him to sell his stake to Link for less than it was actually worth. (Tahari received $53 million as part of the sale; Rosen walked away with $49 million.) Rosen has since called Tahari's lawsuit "a fantasy" and the case is still pending.

On the side

Rosen has been busy backing other aspiring fashion entrepreneurs over the past few years. He provided funding to designer Stacey Bendet of Alice + Olivia and also helped two former Theory employees get started: Lisa Kulson, who launched a line called Kulson, and Iisli founder Nelson Lee.

Off hours

Like his fashion tycoon father (and former boss Barry Schwartz), Rosen is a big fan of the horses. He owns 15 Thoroughbreds (including one named "Fashion Rocks") and had a horse compete in the Kentucky Derby a few years ago. He says that the Daily Racing Form is the first thing he looks at when he wakes up in the morning.

Personal

Rosen and his ex-wife, Adrian Mottola, have two children, Ashley and Austin. Rosen once rented an apartment from Tahari at Trump International, but following the legal rift between the two former partners in 2006, he picked up a 4,200-square-foot duplex in the same building from heiress Libet Johnson for $6.6 million. He has a weekend home in Southampton.