Julie Cooper is the main antagonist in the O.C. She was the main villain in season 1 and 2. She was the anti-hero from 3 and 4. In the middle of season 4, she became a tragic character. Julie grew up in a trailer park in Riverside California. She was a wild child and her sister Cindy had bigger dreams. She never spoken and ignored her parents and her sister for a long time. She met Jimmy Cooper at age 18, was pregnant with Marissa that led her to move out of the trailer park of riverside and to the mansion of Newport Beach. Here she becomes a socialite and high society snob with her daughter Marissa grooming her to be next socialite like her and her daughter Kaitlin who is just like her. She and her husband Jimmy got divorced in the middle of season 1, when he got into trouble with the law where he steals people money from an investment. He was acquitted in that charge. She hooked up with Marissa's ex boyfriend Luke Ward and currently dating Caleb Nichol. Her best friend Kirsten daughter. Caleb is the richest man in Newport Beach and is a multi-billionaire in real estate development called the Newport Group. They had marriage problems, with Caleb wheeling and dealing and bad investments he made. He also spent most of his time looking down his daughter Kirsten and Hailey. Julie spent most of nearly three seasons looking down Ryan Atwood. Mostly she blames him, for making her daughter a mess. It was the other way around, she was to blame for making Marissa the train wreck of this group. Marissa and Julie been estranged for years, they patched things up before she died in the end of season 3. She was also estranged by her other daughter Kaitlin, who was just like her around season 3 and 4, but they patch things up to. That is why Julie Cooper was the gold digger of Newport Beach. She also dated Gordon Bullit and Frank Atwood in season 4, Julie was carrying Frank's son Cooper. She is better mother to him, when she decided to turn her life around since Marissa died and a better mother to Kaitlin who both reformed their ways. Julie in the end of season 4 got her life back together and went back to college and got her degree and flash forward getting her masters degree. She is doing better than I thought.