Derek first appears when he attends his sister, April’s wedding to her Greek fiancé, Nikos. Derek and his father Jim Branning goad Derek's sister, Carol’s boyfriend Alan Jackson, due to their racist attitudes, and try to start fights with him. He lives with his parents and does his best to split Alan and Carol up. He does not succeed, and Carol and Alan marry the same day after April is jilted. Derek and his father walk out of the wedding in protest and Derek continues to goad Carol and Alan after the ceremony. Carol retaliates by humiliating him about still living at home at the age of 36. Derek subsequently attacks Alan, but is stopped by David Wicks, who then beats him up as revenge for Derek beating him up when they were teenagers. A shamed Derek departs. In 1999, Jim mentions to Carol that Derek is going through a messy divorce.
In 2007, Derek's brother, Max, reveals that Derek is in prison, and is therefore unable to attend Bradley's wedding to Stacey Slater. While Derek is incarcerated, he befriends fellow prisoner named Carl White.
In January 2011, Derek is mentioned during an argument between Max and Carol after Max discovers Carol's relationship with Connor Stanley. Max recites Carol's past relationships, including getting pregnant by David when she was 14, and he says Derek sorted David out by beating him up and saving Carol from a broken heart. Derek returns in November, along with Max, who has been staying with him in Leyton. They visit Max's ex-wife Tanya Jessop, (who mutually despises Derek), where Derek recognises her mother Cora Cross and sister Rainie, to whom he is attracted. He reminds her of when they had sex at Max and Tanya's wedding. Derek then recognises David's mother, Pat Evans and forces his way into her home, and she is fearful of him. He reveals he was in prison for 10 years for armed robbery. Carol enters and is not happy to see him. However, Derek says he has changed and wants his family's support, though Carol is unwilling to give it. Derek and Max then prepare to leave for Manchester, but they are stopped by his niece, Lauren Branning, saying that Tanya has cancer and needs help. Max goes to Tanya and Derek tells Carol and his brother Jack that the Brannings have to stick together. Derek starts a sexual relationship with Rainie after she is kicked out of Tanya's home. She then sees a large scar on his back. Derek then bumps into Michael Moon, who he bullied in their youth. Michael fears Derek and after Derek agrees to help Michael's girlfriend Janine Butcher, Michael tells her to keep away from him. Janine then asks Derek to help her get squatters out of her flat, which he does successfully.
When Derek finds out that Phil Mitchell has had Jack's car crushed, he confronts Phil, saying that he has made an enemy of him as well. After the local B&B is destroyed in an explosion, Derek convinces his nephew Liam Butcher to retrieve some valuable copper pipes from the building, leaving his great-grandmother, Pat, infuriated. Shortly after, Derek receives a visit from his probation officer and it is clear that Pat is responsible. Furious, Derek visits her and angrily threatens her, resulting in her collapsing on the kitchen floor shortly after. Pat is then diagnosed with incurable cancer, and when Derek visits her, he teases her about dying, causing a row with Tanya, who suffers a panic attack. Tanya tells Derek to leave. David returns to see Pat, and when Derek sees him, he says they have unfinished business. Derek punches David, who retaliates by punching Derek in the face. Carol takes David's side and drags Derek off David. Carol and Derek later argue, and Carol asks Derek to leave Walford as everyone is sad about Pat's death but he is causing trouble with David. Derek storms off in a temper, and later tells David that the fight is not over. When David hints that he is re-kindling his relationship with Carol, Derek furiously tells him that once Pat's funeral has taken place, he is going to come after him. David tries to reason with Derek, but Derek repeats his threat. When Derek finds Michael in his home planting stolen goods, Michael blames David for the scheme. During Pat's funeral, Derek discovers David and Carol have reunited and are planning to run away together. He confronts Carol and attacks her before forcing Michael to tell David that he has kidnapped Carol. When David shows up looking for Carol, he is confronted by Derek, Max and Jack, and Derek plans to kill David with a knife before getting Jack to help him dispose of the body. However, Jack and Max manage to stop Derek and David flees. Derek then begs Carol for forgiveness for attacking her and explains to Max that he went too far with David. When Phil is arrested for murder and his son Ben is kicked out of his home, Derek befriends Ben in order to steal his keys to Phil's garage. There, he looks through Phil's accounts, and later visits Phil in prison, where he offers to be a partner in Phil's businesses, as they would make a formidable partnership, Phil has no choice but to accept. When Derek asks Michael's half-brothers, Anthony and Tyler for £4000, that they owe him for selling some of his goods, they are unable to pay. Still not having the money to pay, Derek orders them to retrieve copper wire from train tracks but the police are called by Michael which leads to Derek's arrest. He is released without charge and confronts Anthony and Tyler, saying that somebody called the police and because he is still on probation, he is being watched closer and can no longer continue with his dodgy deals. Janine eventually pays off the debt, but Derek gives Michael a beating as well. Derek continues with his criminal behaviour, getting Max to sell a stolen car for him, and getting Alfie Moon to help him with a tax scam, selling alcohol in The Queen Victoria public house that they will claim is being bought for sale in Europe. Roxy Mitchell and Alfie then attempt to intercept the alcohol deliveries to cut Derek out of the scam. Derek urges Jack to fight dirty to get custody of his daughter Amy Mitchell from her mother Roxy, lying to him that he has a daughter, Chrissy. Derek asks one of his contacts, Andy, to scare Roxy into giving Jack custody of Amy, and when Andy tells Derek that Roxy has taken his alcohol, Derek asks Andy to deliver Roxy a message, implied to be that he wants her dead, to make sure Amy stays with the Brannings. Andy knows the Mitchells and does not want to get on the wrong side of them, so pays Roxy the cash that Derek paid him. Derek is then led to believe that Roxy is missing, and Jack is furious at Derek, and especially when he discovers Chrissy does not exist.
When Phil is released from prison, he promptly tells Derek that he no longer needs him to run his businesses. Phil also warns Alfie not to store any more of Derek's goods at The Queen Victoria public house. At a poker game, Phil resoundingly wins against Derek, though Derek claims it is impossible to win all the time, you just have to pick the right battles. Derek arranges with Alfie and Billy Mitchell to steal a large amount of alcohol. However he is unknowingly scammed by Alfie and Billy, and suspects Phil of conning him. Derek realises that Roxy has fallen in love with Alfie, so deliberately sends Alfie off on a job and makes it look to Roxy that he killed Alfie. When Alfie returns safe, Roxy tries to punch Derek for the humiliation he caused her but is restrained by Alfie.
Carol's daughter Bianca is arrested for stealing, and goes to prison in Suffolk. Carol promptly relocates to Suffolk with Bianca's children, However, she allows Derek to move in while they are gone temporarily, and Derek shares the house with Bianca's stepdaughter Whitney and her boyfriend, Tyler. Derek confronts a young woman who appears to be following her, accusing her of being the police. It is in fact his estranged daughter, Alice, who runs off frightened. After she leaves, Derek finds her phone and uses this to track her down, asking her to hear him out. He apologises for abandoning her as an infant and not watching her grow up and Alice admits that she should not have bothered tracking him down. However, Derek asks her to meet with him the next week so he can introduce her to his family, telling her he is a good man who has done bad things. Derek organises a party for Alice so she can meet the family, but just before the party is about to start, Derek is questioned by the police about some stolen alcohol. They do not find the alcohol, and when Derek returns to see Alice, she is already leaving. Derek is angry to discover that Tanya spoke to Alice and scared her away. However, Alice decides to visit, but leaves after revealing that Tanya spoke to her, about which Derek says Tanya is demented and nasty. Derek then threatens to kill Tanya if she says anything else to Alice. Cora shows Alice a letter Derek wrote, so Alice decides to get to know him. He promises to live a crime-free life, but she leaves when she discovers he has been dealing in forged banknotes. Derek then decides to let Alice think he has changed. When Lucy Beale calls Derek's probation officer, saying he is in possession of illegal alcohol, Derek takes revenge by taking money from the tills in Lucy's absent father Ian Beale's businesses. Derek's son Joey Branning arrives, punching Derek. Joey tries to get Alice away from Derek but fails, even after goading Derek into becoming extremely angry. Eventually, Joey cons Derek out of money, which he pays to Lucy. Derek dislikes Alice's relationship with Anthony. The two men play poker, and Anthony bets his business, losing it to Derek. Derek then forces Anthony to leave Walford, leaving Alice upset and angry. She decides to move out but changes her mind when Derek promises to not interfere in her life again. Derek then becomes business partners with Tyler. Derek gives Alice a mobile phone, and he is unhappy when she gets a makeover. He upsets her so much that she goes outside, and is mugged. Derek blames Tanya for giving her the makeover. He inadvertently reveals to Tanya's friend Sharon’s son, Dennis, the truth about how his father died, so Tanya tells Derek to stay away from her family. Max backs her up, so Derek threatens to tell Tanya Max's secret. Alice then tells Derek that it was the phone that caused the mugging and forces him to apologise to Tanya. Derek then guilt-trips Max into making him his best man for his upcoming second wedding to Tanya. Max later tells Derek that Jack is his best man which Derek pretends to take well but is actually hurt. A letter is sent to Carol from David but Derek hides it from her when she returns.
Derek continues to remind Max about his secret, telling him that "they" want more money, and saying he will help as long as he throws Joey out, who is living with Max and his family. Derek discovers that Joey is in a relationship with Lauren, his cousin. Lauren decides she and Joey have to leave Walford, and steal Derek's car. She crashes it into a shop and Derek rescues her and Joey from the building before it explodes. Derek convinces Joey to take the blame to spare Lauren going to jail as she was drunk. Derek then blackmails Joey, telling him to either break up with Lauren or live with Derek and be a doting son, or he will tell the police the truth. Joey decides he hates Derek more than he loves Lauren so ends the relationship. Derek also blackmails Tanya, saying he will tell Max she knew about Joey and Lauren's relationship if she does not convince Joey to stay in Walford. Derek continues to alienate Max and Jack by appointing himself as the new best man for the wedding, and further upsets Jack and his girlfriend Sharon when he discovers Sharon's addiction to painkillers. Derek is beaten up by men involved with Max's secret, and Max gives him money for his honeymoon to pay them off, but Derek does not give it to them. Derek blackmails Tanya again, this time into making Joey leave Walford. At Max's stag party, it is revealed that Kat Moon has been having an affair with Derek. Kat goes home with him and they talk about what has just happened. Derek tells her he loves her. Kat finds a message on his phone that she left for him telling him to leave her alone. Derek says he will play it to her husband Alfie but instead he plays a message in which Kat says she wants to see Derek while Alfie is asleep. Alfie punches Derek, warning him never to return to The Queen Victoria, and hands him his wedding ring.
Derek is confronted by Max who tells him that after Christmas Day, he wants nothing to do with him. Derek arrives at the Branning house for Christmas dinner as head of the family, bringing Kat with him. He is constantly undermined by Max and is shown dislike from many of those present. Kat learns that Derek played Alfie a different message, and then discovers that Derek has deleted all the messages, so she slaps him. As an act of revenge on Max, Derek calls the person involved in Max's secret, and she arrives moments before Max and Tanya are due to remarry. She introduces herself as Kirsty Branning (Kierston Wareing), Max's wife, whom he married while staying with Derek in 2011. It is revealed that Derek never handed Kirsty Max's divorce papers or the money that Max was giving to her, but allowed Max to think they were divorced, and did not tell Max about Kirsty's pregnancy, instead telling Kirsty that Max wanted the child aborted, which she did. A massive argument ensues and Derek shouts at Max and Jack, saying he has never liked Max and he was the person who locked him in a coffin as a child (Max had believed it was Jim). Derek is forced out of the house by Max, Jack and Joey, while Kat watches on. He then suffers a heart attack on the street and dies.