MTV Films Laguna's Kids

MTV approaches Cavallari, Lauren Conrad and a group of friends to document their lives in the affluent California beach town of Laguna Beach. The show, Laguna Beach: The Real Orange County, premieres in September 2004 to compete against FOX's teen drama The O.C. "It really was presented to us like a documentary," Conrad tells USA Today. "Nobody thought it was going to blow up like it did...definitely a different way to grow up." The MTV reality series turns Cavallari, Conrad and the boy they fought over, Stephen Colletti, into stars.

Spring 2005

Kristin & Brody Jenner

Fellow Laguna star Talan Torriero introduces Cavallari to his friend Brody Jenner. The two begin dating, and Cavallari calls their love her "first mature relationship." She tells Teen People, "He's good-looking and he makes me laugh for hours." In August 2006, after about a year of dating, they call it quits.

Dating Nick Zano

Cavallari quickly finds love again with former MTV personality and What I Like About You star Nick Zano. When they break it off at the end of 2007, the reality TV star gets Zano's initials removed from her left wrist.

September 29

A 'Bitch' of an Ending

Cavallari brings the drama in the season 5, part 2 premiere of The Hills, fighting with Patridge and Stephanie Pratt – who says, "She's the girl that's going to stab us all in the back." In July 2010, she gives The Hills a surprise Hollywood ending that shocks fans. "We couldn’t have asked for a better ending," she tells PEOPLE.

July

Far From a Fairytale

Three months after getting engaged, Cavallari is reportedly "dumped" by Chicago Bears quarterback Jay Cutler, who calls off their engagement. "She's in shock that the dream wedding she was planning is going to end this way," a source tells PEOPLE of the bride-to-be, who was busy planning a spring wedding. "Jay Cutler was beyond controlling and didn't really like Kristin to go out," a friend of Cavallari said of their relationship. "I'm not surprised it didn't last."