Joseph is born prematurely to parents Chris and Rachel, and named after Rachel's stepfather Joe Sugden and Rachel's brother Mark Hughes. Since Chris and his dad Frank Tate are away in a meeting when Rachel goes into labour, Chris' former wife Kathy Brookman helps Rachel and becomes Joseph's godmother. When Chris and Rachel divorce, Rachel obtains custody of Joseph. The following year, Rachel begins a relationship with Graham Clark, who later murders her by pushing her off a cliff. Joseph begins living with Chris, although when Chris marries Charity Dingle, Joseph opts to attend boarding school. Two years later, Chris commits suicide, framing Charity for his murder and leaving Joseph an orphan. Zoe Tate, Chris' sister, obtains custody of Joseph and in 2005, they leave the village with Zoe's daughter, Jean Tate.
Twelve years after leaving the village, Joseph returns to Emmerdale, using the alias Tom Waterhouse. He meets Debbie Dingle about leasing a Bentley. Tom and Debbie later kiss and sleep together, he then buys her a Bentley and a house, Jacob's Fold. They begin a relationship. Debbie soon discovers that Tom has invested in a golf course that is to be built on the land that the Dingles' cottage, Wishing Well, is built on. Joseph reveals his true identity, takes back the Bentley, evicts Debbie and her children, Sarah and Jack Sugden, out of Jacob's Fold and ends his relationship with Debbie, telling her that she was collateral damage in his pursuit of seeking revenge on her mother, Charity, for driving his father, Chris, to suicide. Joseph buys his childhood home, Home Farm, from the Whites and later moves into it. He makes up with Debbie and starts a relationship with his brother Noah Dingle.
On 11th October 2018, Joe is seemingly killed when he hits his head on a rock after a single punch by Debbie's father, Cain Dingle. However, when Graham puts Joe in the boot of his car, Joe's hand twitches. Graham is then seen emotionally breaking down at the wheel of his car. Graham later confirms to his step-grandmother Kim Tate that Joe has been taken care of, and Joe was assumed to be dead. However, on 18th March 2019, Joe was revealed to be alive and living abroad, living off money from Kim's business.
1995-2005: Early life and becoming an orphanRachel gave birth to 6lb 2oz Joseph five weeks prematurely on 8th June 1995 with the aid of Chris' soon-to-be ex-wife Kathy. Rachel named her son Joseph Mark after her step-father Joe Sugden, who had died a few days prior, and her late brother Mark Hughes. Kathy became Joseph's godmother. Chris' father Frank was disappointed that Chris and Rachel didn't get married before their son was born so when Joseph was six months old, Rachel and Chris tied the knot in secret. Frank got emotionally attached to his grandson and tried to help Chris and Rachel bring Joe up but Chris told his dad to back off a bit. Chris and Rachel split after less than a year of marriage due to disagreements about family planning. Joseph went to live with Rachel and had regular visits with Chris.In May 1999, Rachel was murdered by her boyfriend Graham Clark so Joseph went to live with Chris. A few years later, Chris married former prostitute Charity Dingle and Joseph was sent to boarding school.
In 2003, whilst Chris and Charity's marriage was on the rocks, Chris learned he had an incurable brain tumour. Chris knew Charity was having an affair with her cousin Cain so he committed suicide and framed Charity for his murder, leaving Joseph an orphan. Pregnant Charity was found guilty of Chris' murder but was acquitted after she agreed to give Chris' sister Zoe custody of her and Chris' newborn son Noah in return for the evidence that would clear her. Charity later took back custody of Noah. In September 2005, Joseph immigrated to New Zealand with Zoe and her young daughter Jean.
2005-2017: School years
Growing up, Joe started to develop attachment issues. In 2008, One night, after school groundskeeper Graham Foster had drunkenly set his hut on fire, Joe saved him and they soon bonded. Graham became a father figure in his life and Zoe made him Joe's guardian to prevent him from being expelled. 2 years later, when he was 15, he locked his headmaster in a cupboard.
2017-2018: Life as Tom WaterhouseBy 2017 Joseph, now known as Joe, had returned to Yorkshire and had used his substantial inheritance to set up Waterhouse International. Under the alias of Tom Waterhouse, he contacted Charity's daughter Debbie Dingle about hiring her Bentley. Whilst Charity and Debbie were in a meeting with Tom's right-hand man Graham Foster, their Bentley was stolen. Tom gifted Debbie a new Bentley and they soon began a relationship. Tom lavished Debbie with expensive gifts and even bought Jacobs Fold for her and her children Sarah and Jack to live in. Against Graham's advice, Tom gave Debbie a job. On her first day at Waterhouse International, Debbie discovered Tom was behind the Dale Woods Golf Course project which was trying to force the demolition of Debbie's family's home to make way for an access road. Debbie forgave Tom as he spun her a tale about only finding out the project would affect her family when it was too late, lying he kept it all from her because he didn't want to lose her.
Charity was suspicious of Tom so she set off the fire alarm at his office building and searched his office where she found his passport and discovered Tom was lying about his identity - he was really her former step-son Joseph Tate. Charity tried to warn Debbie but Joe intercepted Charity's call and sent Graham to stall Charity. Whilst Graham was keeping Charity busy, Joe arranged for the Bentley to be taken away and for Debbie's belongings to be moved out of Jacobs Fold. Joe revealed to perplexed Debbie that he was really Joseph Tate, she was just collateral damage in his quest to get revenge on Charity for his father's death. Joe then bought back his childhood home of Home Farm.
2018-2019: Relationship with Debbie and presumed deathAfter Joe revealed himself, Debbie trusted him less until Graham helped Debbie and Joe get back together. Joe knocked down the Dingle home which Debbie confronted him about and to get revenge Debbie asked Simon to hurt Joe. Instead, Simon threw acid in Ross Barton's face. Debbie and Joe rekindled their relationship and got engaged, and he asked to marry Debbie at the hospital chapel but had to deal with the masquerade ball. Unfortunately, Joe had to go on the run after his step-grandmother Kim, who had just returned after being released from prison, wanted Graham to kill him, he left with £100,000. Furious about what Joe did to Debbie, Cain punched Joe which caused Joe to fall and hit his head off a rock, and it was believed that Graham later finished the job to avoid Kim from hiring someone else to give him a more painful death.
2019: Living abroad
Joe was presumed dead for the next five months, with everyone in the village assuming that he had fled. Cain, on the other hand, was riddled with guilt as he thought that he killed Joe. Joe was subsequently reported as a missing person, and Cain confessed to Debbie that he killed Joe, which resulted in the breakdown of their relationship.
Kim returned to Home Farm after she was re-released from prison and found out that it was Cain who "killed" Joe. Kim met with an associate to find out who was making withdrawals from an offshore account and discovered through CCTV pictures that Joe was alive and had been taking money out from the account in Monte Carlo. Kim confronted Graham about this, and he revealed that Joe is no longer in Monte Carlo as he moved him on.
- Joe was a shareholder in Emmerdale Farm as his step-great-grandmother Annie Sugden gave him some shares when he was born.
- Joe "caught" the flower bouquet at his mother Rachel's wedding to his father Chris in December 1995.
- Joe supports Leeds United.
- Joe was axed alongside Jean Tate Jr. in September 2005 following Leah Bracknell's decision to leave the role of Zoe Tate.
- Joe was reintroduced by producer Iain MacLeod in September 2017. He was the only character with the Tate family name to be reintroduced until Kim Tate's return in October 2018.
"Here I am dressed like a penguin" - to Debbie Dingle, after she thinks he is a butler.
"FINALLY she gets it!" - to Debbie Dingle after she realises his plan.
"If I wanted a prostitute, I would just pay for one." - to Debbie Dingle, who slaps him moments later.
"If you're going to back a horse, Ross... always back the thoroughbred, not the inbred." - to Ross Barton about Debbie Dingle.
"You are my little brother, and you're the closest family I've got." - to his little half-brother Noah Dingle.
"Just let me explain." - final line, to Cain Dingle before Cain punches him severely.