After graduating high school, Colorado-native Heidi Montag heads to California to crack the books at the Academy of Art University in San Francisco. At a freshman orientation, she meets Lauren Conrad, star of MTV’s hit reality show, Laguna Beach. "Everyone in the room was kind of gothy, and we were the two blond girls in the room scared out of our minds," Montag recalls to the New York Times in 2006. "I ran up to her and said, 'Will you please talk to me.'" Soon after, the new friends plot their move to L.A. to study at the Fashion Institute of Design and Merchandising.
MTV develops a spinoff with Conrad called The Hills, featuring Conrad's move to L.A. as she studies fashion, interns at Teen Vogue, and lives with Montag. (From left, costar Audrina Patridge, fellow intern Whitney Port and Conrad). Creator Adam DiVello tells PEOPLE, "It's really about the next stage in life, when you leave high school and leave home for the first time." In the first season, Montag drops out of FIDM to work for the event-planning firm, Bolthouse Productions.
During the second season of the hit show, tension surfaces between Montag and Conrad when Montag begins dating instigating bad boy, Spencer Pratt. Montag eventually moves in with Pratt, ignoring Conrad's warning of his wandering eye and her prediction that it will ruin their friendship. Conrad is also hurt when the couple urges her friend, Jen Bunney, to hook up with her ex, Brody Jenner. "I ... felt so betrayed," Conrad tells Montag.
Montag gets a nose job and breast augmentation, taking her bust size from an A-cup to a voluptuous 32C. "It was really something that had been tormenting me and I was very insecure about it," she tells Access Hollywood of her pre-surgery looks. "I thought about it for several years and I waited until I had the finances and really thought about it and was old enough to really make a mature decision."
Word spreads that Conrad made a sex tape with ex-boyfriend, Jason Wahler, but they both adamantly deny the rumors. And Conrad soon predicts that Montag and Pratt started the sex tape rumor. Pratt posts vulgar comments about Conrad on his Web site: "It's sad that she destroyed the sex tape...[It] would have made her real famous."
"You know what you did!" Conrad repeatedly screams at Montag during a confrontation captured in the third season premiere of The Hills. Conrad calls Montag "sad," while Conrad's new roommate Audrina Patridge calls Montag "brainwashed" by Pratt, who has been bad-mouthing Conrad in the press. Although many question the show's authenticity, the LC-Speidi feud helps drive ratings, drawing in 3.6 million viewers and making the premiere the highest rated show for MTV this year.
Although Pratt tells EW, "We would get engaged; we just wouldn't do it on Lauren's show," he does just that. Around that time, Montag appears on CosmoGIRL!, but readers of the teen mag question editors' judgment. They call Montag "plastic and fake" and say she "trashed her best friend." An editor responds, "I just wish everyone would cut Heidi a little slack. Just imagine if you and your best friend got into some huge fight, and for whatever reason, you were never allowed to tell your side of the story, but your friend could, and everyone believed her."
With her new look, Montag appears on the cover of Maxim, where she says, "[Lauren's] changed. Some people go more Hollywood than others...I’ve heard from other people that she’s a big diva now." Of their so-called reality show, Montag explains that it’s "22 minutes" that’s "edited for drama...They’re not with us all the time, although I wish they were, because it would be a way crazier show. Let’s see how Lauren would look then!"
Attempting to breakthrough as a singer, Montag releases her music video, "Higher," which receives an almost unanimously negative reception by PEOPLE.com readers. Directed by her faithful Pratt and featuring a bikini-clad Montag romping across a beach, the underperforming video is shot in 30 minutes, independently, for "zero dollars." "All negative energy," Montag tells PEOPLE. "I completely ignore it."
Montag, 21, and Conrad, 22, appear together – with Audrina Patridge, 22, and Whitney Port, 23 – on the cover of Rolling Stone. The shoot is the first time the two frenemies have been photographed together since their ratings-boosting feud. The magazine calls The Hills – which an MTV exec calls "the most influential show we've ever had" – "a maddeningly addictive TV show in which nothing ever really happens." "Who were Paris and Nicole before they weren't friends? That's when they became superstars," Montag's Pratt says. "If Lauren and Heidi were friends, people wouldn't tune in."
BIOGRAPHY (top to bottom): Alexandra Wyman/WireImage; MTV; Matt Sayles/AP, Katy Winn/Getty; Jean-Paul Aussenard/WireImage; James Breeden/PacificCoastNews; Courtesy of Rolling Stone