In 2000, Charlie, a widowed taxi driver whose wife Viv Slater died in 1999, arrived in Walford with his mother-in-law Mo Harris, daughters Lynne, Kat, Little Mo, and Zoe, plus Lynne's boyfriend, Garry Hobbs.
It soon emerges that Kat is actually Zoe's mother and that it has been kept a family secret until Zoe finds out. Demanding to know the identity of her birth father, Zoe and Charlie are stunned to discover that it was Charlie's brother Harry. Zoe runs away after the revelation and when she returns, the family discover that she has been living with an old school friend Kelly Taylor in a brothel, where they worked as prostitutes. Soon after, Kelly arrives in Walford and Charlie agrees that she can stay with them, which she does so for two years.
Little Mo, normally a timid and shy young woman, assaults her husband Trevor Morgan with an iron. The family learn that Trevor has been domestically abusing Little Mo. Worse comes when Little Mo is found guilty of attempted murder and sentenced to eight years in prison. The family appeal and a retrial is ordered. In exchange for Kat not pressing charges against Trevor for assaulting her, he agrees not to testify against Mo. She is released and comes back to live with her family.
Two years later Little Mo, now married to Billy Mitchell, is sexually abused in The Queen Victoria public house by Graham Foster. When Charlie finds out, he attacks Graham after locking him in his taxi. Charlie is arrested and remanded in custody for grievous bodily harm, to which he pleads guilty but the family has to pay Graham £10,000 compensation. Charlie's taxi license is revoked, but is later restored. Little Mo discovers she is pregnant and is advised by her family to have an abortion, but she refuses and leaves Walford. Lynne, now married to Garry, is expecting a baby, however, she is injured when a fairground ride collapses and she suffers a placental abruption, meaning she needs an emergency Caesarean section. The baby dies and Lynne is only saved by a hysterectomy. Devastated, she leaves Walford. Charlie's great-niece Stacey Slater (Lacey Turner) arrives and moves in, and Charlie becomes a father figure to her, helping her curb her rebellious and wayward attitude. At the same time, he comforts Zoe after she has an abortion. Zoe eventually leaves Albert Square, soon followed by Kat who is now married to Alfie Moon. However, Stacey's mother Jean moves in with the family. Stacey's brother Sean also moves in to Charlie's house for a time, though Charlie dislikes him, and he soon moves out.
Charlie puts an advertisement in a lonely hearts column and becomes a member of an internet dating website, meeting and falling for Brenda Boyle, a Salvation Army member from Clacton. However, their romance begins to fizzle out. After not seeing each other for several weeks, Brenda ends the relationship, telling Charlie that she and her brother are moving to Madeira. Not wishing to end the relationship, Charlie gets approval from Stacey and Mo to go with her. He returns not long after with a Russian woman named Orlenda (Mary Tamm). Mo is suspicious of her and follows her around. On seeing her with another man, Mo takes a photo to show Charlie. Charlie confronts Orlenda who admits that she was using Charlie for his money and he asks her to leave.
When Stacey stops taking medication for her bipolar disorder, Charlie insists that she has to start again as she almost lost her baby Lily. Charlie asks Dot Branning to speak to Stacey as he believes that Lily's father is Stacey's deceased husband Bradley, Dot's step-grandson. Dot then reveals that Lily is not Bradleys. Charlie asks Stacey why she has not told the truth and begs her to take her pills, trying to force one into her mouth. Stacey says she has already taken them and Charlie apologises, then walks out of the house in tears.
He spends the night at Patrick Trueman's house, and invites Patrick and Jim Branning for drinks. Later, Sam Mitchell asks Charlie to take her to the hospital because she is worried her baby Richard is unwell, however after driving part way, Charlie tells her the symptoms are normal. As he turns around, he reverses into some boxes in front of a van, and is then stopped by a police officer (Laurence Mitchell). The next day, Mo opens a letter for Charlie and learns was caught driving over the limit. They argue as he could lose his driving licence, and Charlie later apologises to Stacey for forcing her to take her pills.
Charlie is shocked when his daughter Kat returns to Albert Square. Kat is trying to avoid some thugs to whom she owes money. They catch up with her at Charlie's house, and Kat tries to escape. In the commotion, Charlie reminds Kat that she hasn't even asked about his life or anyone else's in Walford. Kat's estranged husband Alfie then arrives and chases the thugs away. However, Charlie is then dismayed to learn that Kat is pregnant, and Alfie is not the father. Alfie and Kat reopen The Queen Victoria as landlords and give Charlie a job there as a potman.
Kat gives birth to Tommy, on the same day Ronnie Branning gives birth. Kat is rushed to hospital, leaving Tommy in Charlie's care, but he joins the New Year Eve's party instead. Ronnie's baby dies of cot death and she secretly swaps the babies. Alfie and the rest of the family then discover the dead baby, believing it to be Tommy. Charlie admits to Kat that the baby was left alone as he was drinking, so Kat blames him for the death. Charlie tries to make things right, but eventually realises it is best for him to leave. Mo begs him to stay but he refuses. Mo tells Kat and Alfie, and when Alfie says dads have feelings too, they run to the tube station. Kat forgives Charlie and he leaves to stay with Lynne.
When Kat and Alfie receive Tommy back in April 2011, Charlie visits Kat and helps her bond with her son. Kat asks Charlie to return to Walford, but he refuses as he is in a relationship with a younger woman named Eileen, and they are getting married. Soon after, he returns to Lynne's.
Charlie suffered a stroke in January 2012, which led to daughter Kat caring for him for six months off-screen.
Charlie came back for one last appearance, due to the stress of Kat and Mo arguing he ended up suffering a fatal heart attack and sadly passed away on January 7th 2016.