Harold "Harry" Slater is the younger brother of Charlie Slater, the father of Zoe Slater, and the uncle of Lynne Hobbs, Kat Slater, Belinda Peacock and Little Mo Mitchell, the second of whom, Kat, he raped.
Harry had groomed his niece, Kat, as a child. When Kat was 13 years old, Harry started sexually abusing her, resulting in the birth of Zoe Slater. Charlie was unaware of who Zoe's father was, so he made the decision to raise Zoe as his own daughter, with Kat taking on the role of Zoe's sister. Soon after the incident Harry moved to Spain and didn't appear until the death of his sister Violet in 1988. After Violet's funeral, Harry quickly returned to Spain.
Harry arrives in Walford on the 3rd May 2001 to visit his older brother, Charlie. Harry falls in love with Peggy Mitchell and they quickly make plans to marry and emigrate to Spain, where Harry lives. Zoe announces to the family that she is leaving Walford to live with Harry in Spain. Kat is furious at the announcement and refuses to let Zoe go.
Zoe storms out saying she's leaving and Kat follows after her. The two argue and Kat shouts that she is her mother. When Zoe demands that Kat tell her who her real father is, Kat shocks her by revealing that it's Harry. Charlie discovers this and goes to find Harry and attacks him in The Queen Victoria public house, but is restrained by the punters. Charlie threatens Harry to leave Walford, telling him to never return again otherwise he will murder him. He also warns that he is to end his engagement with Peggy and he does so by writing her a letter. He arrives at the Slaters' saying he is ashamed of his actions and that it's ruined his life. He admits that Viv told him to leave, revealing the reason he went to Spain suddenly a couple of weeks after it happened. He goes to shake Charlie's hand to say goodbye but Charlie, disgusted by him, spits in his face calling him a monster. Kat confronts Harry and he says she must hate him. She denies that she hates him but just thinks he's a pervert.
Kat reveals that Harry got her pregnant and tells him that Zoe is the child. She says that Zoe hates him for what he did to Kat. Harry calls Kat a bitch and leaves in a taxi. Kat attempts suicide but is found in the park by Zoe and is rushed to hospital. The following year, Charlie receives news that Harry has died from a heart attack. Harry leaves Zoe £18,000 in his will, but when Zoe sees how much the idea of taking anything from Harry is upsetting Kat, she burns the cheque saying she doesn't need his money.
- Episode 2104 (3 May 2001)
- Episode 2105 (7 May 2001)
- Episode 2106 (8 May 2001)
- Episode 2111 (21 May 2001)
- Episode 2112 (22 May 2001)
- Episode 2113 (24 May 2001)
- Episode 2114 (28 May 2001)
- Episode 2115 (29 May 2001)
- Episode 2116 (31 May 2001)
- Episode 2143 (2 August 2001)
- Episode 2144 (6 August 2001)
- Episode 2145 (7 August 2001)
- Episode 2146 (9 August 2001)
- Episode 2147 (10 August 2001)
- Episode 2148 (13 August 2001)
- Episode 2178 (4 October 2001)