Clarke is a conniving womanizer and fashion designer, always willing to put himself into trouble to live the high-life and get the recognition he feels he deserves.
Thinking her daughter Kristen was too close to her father Eric, Stephanie Forrester hired this ambitious Spectra Fashions designer in 1987 to romance her daughter. But the girl was not interested and soon Stephanie chose not to pursue the deal. Adamant he had to bond with someone in the family to get a job at Forrester's Creations, Clarke soon decided to go after another Forrester woman: Stephanie herself. She hesitated for a while about having an affair with Clarke but quickly decided against it. In the meantime however Kristen finally agreed to start a relationship with him. She then proceeded to pass Clarke's designs as her own. Clarke was thrilled when Eric found out - he was forced to hire him since he already had used the designs in his collection.
While insisting his feelings for Kristen were genuine to a dubious Ridge, he started to date Margo Linley, Eric's assistant. Kristen and Clarke finally decided to elope to Las Vegas in 1988. But soon thereafter Margo admitted to him that she was pregnant with his child. Since Clarke refused to do anything about it, Margo decided to blackmail him for $100,000 as child support. Clarke turned to his ex-boss Sally Spectra for a loan to pay Margo. Using this as an opportunity, Sally agreed only if in exchange Clarke stole 6 Forrester Originals which she planned to pass of as her own. Even though Kristen soon discovered the truth about the baby and forgave him (making the whole deal pointless), Clarke was still blackmailed by Sally (because he agreed to steal for her), but chose to create some new sketches, although he told her they were Forrester Originals. Sally discovered the truth but Clarke's dresses were well received, so she suggested hat he continue to design for Forrester while also working for Spectra at the same time, using the alias "Beau Rivage."
Although married to Bill, some say Margo continued to hope to have a family with Clarke. She decided to start plotting with Mick Savage, Kristen's old flame and new Forrester's photographer, to break up Clarke's marriage. Margo found herself also happy when Clarke acknowledged Mark as his son, after the boy was admitted to hospital with a high fever. In the meantime, Clarke and Kristen finally realized that their marriage led them nowhere and Kristen left town with Mick. As Clarke found himself unemployed, Sally offered him a deal: she'd give him half of Spectra and his own label if he married her. Clarke agreed to think about it but asked Margo if she would leave Bill for him. Having discovered that Bill was setting up a trust fund for Mark, Margo chose to stay married to him. Sally changed her mind in the meantime but Clarke forced her to go through with the deal by having an article published explaining that he and Sally were engaged. Sally didn't trust him though and had him sign a pre-nuptial agreement.
Soon after they got married, Clarke made a move on Julie Delorean, Bill's spy at Spectra, who had fallen for him. But soon Clarke backed away. Outraged, Julie handed the complete manuscript of a 'tell-all' book about Clarke to Bill. Sally announced at the time that she was pregnant. A furious Clarke ordered her to go and get an abortion, which Sally led Clarke to believe she did. Bill then sent a copy of the book to Sally. Upon realizing that she no longer needed Clarke, as Felicia's line was very successful and after finally understanding he cheated on her with Julie, Sally had Clarke fired, leaving him penniless. Clarke refused to give up his paternal rights when Bill offered him $100,000. Clarke tried to apologize to Sally, to no avail. As she was forced to admit she was still pregnant with his child, Clarke used the childbirth classes to bond with his wife again, until she gave birth to their son, Clarke Jr. Sally finally rehired Clarke, as the company was in trouble again. Everything seemed even all the brighter for her when an envelope was delivered to Sally, containing the Forrester's BeLieF formula, leading her to believe maybe Clarke stole it to give her, even though he denied it.
Clarke was very happy to finally have a successful line but was unhappy with his sex life with Sally. He finally got out of it by pretending to be impotent. As she was trying to seduce him as a "test", Darla overheard Clarke planning to leave Sally after their second anniversary when he received 50% of Spectra, according to their premarital agreement. Crushed, Sally found out there was no way to cancel the agreement, unless Clarke had been unfaithful. Desperate to set him up, the Spectra family finally got him when, as he thought he had reached the deadline, he made love to Kristen (who had come back for a little while). Thanks to the videotape, even though she was aware Spectra was lost without Clarke as its designer, Sally threw him out, as Kristen dumped him as well, forcing him to leave L.A.
In 1996, as Spectra was on the verge of another bankruptcy, a desperate Macy tried to save the company by contacting Clarke and rehiring him as Spectra's designer. The problem was C.J. felt a bitter resentment towards Clarke because he abandoned him as a baby. The boy claimed he didn't want his father to be part of their life, as Clarke on the other hand did his best to build a relationship with his son, including lying that he turned down an offer to work for a world famous designer called Antonio Giovanni just to be with C.J. Clarke hadn't changed one bit: he was receiving bribes from Unicorn Fashions, a rival company of Spectra, to sabotage Spectra's line by designing awful clothes. He had a change of heart at the last minute. Furious, the guys at Unicorn kidnapped C.J. and tried to kill him. Clarke almost died while trying to save his son, but he pulled through and bonded with C.J..
Clarke then started a relationship with the young Michael Lai. But Grant Chambers, a new designer at Forrester Creations, punched Clarke after seeing him in Michael's office. In fact years ago Clarke had mistreated Grant's sister, Kelly, and Grant strongly advised Michael to stay away from him. Michael and Grant began to date anyway and she soon dumped Clarke. Clarke later got a revenge on Grant and realized his long-time dream of working at Forrester Creations again (revived when Sally refused to give him stocks in Spectra) when he randomly discovered that Grant and Brooke's marriage was invalid and blackmailed Thorne into revealing him the news against a new position at the company. After Grant's death, C.J. convinced his dad to return to Spectra fashions. Clarke reluctantly accepted because he had grown tired of the Forrester's lack of recognition and because he was willing to show his son he loved him.
Later Clarke befriended and had actually a real crush on Morgan DeWitt, and became her confidante. He was thrilled when he discovered she got Ridge to impregnate her, although he was jealous of her feelings for him. Even if he promised her the secrecy, Clarke couldn't help blackmailing Ridge, whom he felt had treated him badly for all these years. Furious at his betrayal Morgan released a python into his office while he was sleeping, which almost killed him. Even though he survived, Clarke was paralyzed for a short time but never revealed to anyone Morgan's responsibility into this. Kristen Forrester came back to town shortly thereafter and Clarke had renewed interest in her. But Kristen only had eyes for HIV positive Tony. Despite Clarke's best efforts, Kristen chose to be with Tony.
In the fall of 2002, Clarke's son, Mark, returned to LA. In his time away from home, Mark had changed his surname - to Maclaine - and he finished medical school. Upon finishing med school, Mark took a job at an LA emergency room so he could be in the same city as his father. Mark introduced himself to his father, despite his mother's objections. Clarke and Mark worked out their problems about Clark abandoning Mark and they decided to reconnect and try to work on their relationship. Clarke also had to start playing referee between Mark and his other son, C.J., when they both started dating the same woman -- Bridget Forrester.
Clarke's role was diminished in recent years, and it wasn't until he accepted Nick's offer to become head designer at Forrester Creations that he began to be a major player again.