Originally, the residents of Salem believed that Belle was the daughter of Marlena and Roman. In truth, Belle was the product of a one-night-affair between Marlena and John Black.

Belle's true parentage might never have been revealed if it weren't for her older sister Sami who discovered the truth and kept the secret for several months. She even kidnapped Belle and tried to have her legally adopted! In the end, however, it was Stefano DiMera who revealed the truth after reading Sami's diary. During her formidable teen years at Salem High School, Belle started an ill-fated relationship with (at the time) bad boy Philip Kiriakis, but soon devoted all her attention to Shawn Brady. She also added new girl Chloe Lane to her circle of friends. All of her peers were shocked to see her spending time with "Ghoul Girl" Chloe, but eventually everyone accepted their friendship. Belle joined her fellow teens on a trip to Puerto Rico, where they were supposed to study the environment. Instead, she, Shawn and Philip went on an adventure to find some missing jewels, including a ruby belonging to Alice Horton. Much to the dismay of the criminally-minded Paul, the teens were successful and Shawn was able to return the ruby to his grandmother. Instead, she, Shawn and Philip went on an adventure to find some missing jewels, including a ruby belonging to Alice Horton. Once back in Salem, Jan continued to confide in Shawn her pregnancy as a result of her rape by Paul on the island. Shawn agreed to stand by her and say he was the father, even though this destroyed his relationship with Belle. She was devastated and couldn't believe someone she had trusted as much as Shawn could hurt her like this. However, she made it through her senior year at Salem High and when, at the end of the year, the truth about Jan and Shawn came out, Belle managed to forgive him and they were reunited at the Last Blast Dance. She forgave him, but was still tentative about their relationship. That same summer, during the Gemini meteor showers on the Fourth of July, Belle and Shawn got the surprise of their lives up at Lookout Point when an apparent alien space ship landed. They rescued the aliens and spent the rest of the summer looking after them and keeping them hidden from the rest of Salem. Shawn often wanted to turn them in, but Belle never gave up her strong desire to help her twin alien friends. The government though, with the help of Belle's father John, took Rex and Cassie, the "aliens" into custody and discovered they were really human. Belle started college at Salem University, where she lived in Hartley House, an on-campus dorm, with Shawn. Rex and Cassie also moved into the dorm, and Mimi lived at home while attending college. Belle still had to deal with Cassie's unstoppable attraction to Shawn, among other problems. Belle and Shawn did commit to their future together, though. They each wear purity rings, signifying this commitment. Shawn and Belle suffered another set-back after Victor and Nicole's New Year's Eve wedding at which Colin Murphy was murdered. Shawn had shot at Colin and missed, but he thought he was responsible. Shawn broke up with Belle to deal with it on his own. She didn't understand why, but they were finally reunited after Larry Welch (falsely) confessed to the crime. Meantime, Belle had started working as an intern for Basic Black. Her work ethic contrasted with Shawn's more easy-going approach to life, causing her eventually to break up with him. While they were separated, she went on a reality show, Love is Blind, with Cassie and Mimi. Belle won the game and her prize was a date with a blindfolded hunk. He turned out to be Philip Kiriakis, now stationed on a Marine base near Salem. But was he just a Marine? Turns out, he was a member of the ISA and Belle nearly got into trouble several times when she was with him. Belle's lingerie and swimwear designs were featured in a Basic Black fashion show with a very unhappy ending; Bo and Hope were attacked. They survived and so did her future as a fashion designer. When she became horribly distraught over the murders of the Salem Stalker -- even removing her purity ring and wanting to live for the moment -- her father and Shawn conspired to send her to Europe on Basic Black business. She returned for the holiday season and to her life with Shawn. Of course, the Salem Stalker was still at work. Nine people in total were murdered before the killer -- Belle's own mother! -- was finally caught. Belle was devastated and could not believe that her mother was guilty. She even lied to Shawn to provide an alibi for one of the murders, then lived to regret it. Shawn's own grandmother was the next to go and, overcome by guilt, he left town to clear his head. But Belle wasn't alone for long. Philip, who is harboring a secret crush on her, moved in to provide solace.

Although she resisted, Belle eventually gave in to Philip's charms. It didn't help that when Shawn finally returned, his personality was completely changed. He expressed hatred for Belle and for Philip and hooked up with Jan. Philip and Belle became engaged and Shawn's feelings about them didn't change until the night of their wedding. He realized he was still in love with Belle and crashed the wedding -- literally. He drove his motorcycle through the stained glass window of the church, very nearly killing himself and his beloved in the process. And he didn't even stop the wedding. So Belle and Philip were married, but she knew she was still in love with Shawn. She wanted to tell Philip the truth, but he shipped out with his Marine unit and was taken hostage. It wasn't long before Shawn headed out to rescue Philip, knowing Belle wouldn't be with him as long as her husband was missing. Will Shawn succeed? And if he does, will Belle dump her husband for him?