Ashley lands her first major magazine cover without Mary-Kate. Harper's Bazaar declares Ashley, "Fashion's New 'It' Girl," highlighting her and Mary-Kate's "dumpster dressing" and "bobo" (bohemian bourgeois) style. "I honestly don't know why we started dressing like that," Ashley tells Harper's Bazaar. Of Mary-Kate she adds: "We support each other always. We've always had differences. It's just that now, for the first time, the public is starting to see it that way." That September, the 19-year-old begins dating Tsubi jeans CEO Greg Chait, 27.
Ashley and Mary-Kate debut as high-fashion models for designer team Badgley Mischka. "They really are like one mind in two bodies," James Mischka tells PEOPLE. In August, they both appear in a Vogue fashion spread titled "Billion-Dollar Babies," which praises them for their individual style unaided by celebrity stylists. "It is very inspiring for a designer to see his designs interpreted by the right girl," designer Karl Lagerfeld says. Ashley also shares cover girl duties with Mary-Kate in December for Teen Vogue.
Ashley and Mary-Kate launch a high-end women's wear line called The Row. They codesign the knitwear collection of tees, cropped jackets, skinny pants and cashmere vests with their friend Danielle Sherman. Ashley tells Vogue that their collection is "about the clothing – not the people behind it." The following year, they launch Elizabeth and James, a lower-priced alternative to The Row.
The twenty-year-olds top Forbes' list of Young Hollywood's Top Earners and place 37th on Forbes' Most Powerful Celebrities list. In 2006, they pulled in a combined $40 million from their Dualstar earnings and fashion ads.
Ashley, 21, is linked to former Tour de France champ Lance Armstrong, 36. The pair is first spotted at the Rose Bar inside New York's Gramercy Park Hotel, where an observer tells PEOPLE, "[Olsen] was very flirtatious, and was sitting on his lap." They reunite again in the wee hours at hip restaurant the Waverly Inn. Reps for both stars have no comment.
The 22-year-old twins release their coffee table book, Influence. "We have filled Influence with the most interesting, challenging, creative people we know – the ones who helped pave the way for us and our generation," Ashley says of the book that serves as a window into what has helped shape them.
Ashley begins dating Hangover star Justin Bartha, whom she's spotted with from L.A. and New York to Las Vegas. "It's more important than anything else in the world," she tells Marie Claire of her relationship with the actor in 2009. Though the pair are rumored to be engaged, they call it quits after two years together in early 2011.
BIOGRAPHY (top to bottom): Harper's Bazaar; Courtesy Badgley-Mischka; Peter Kramer/Getty; Jennifer Graylock/JPI, Jeff Vespa/WireImage; arion Curtis/Startraks