Zak first appeared in 1994, challenging old adversary Ned Glover to a bare-knuckle fight, which he went on to lose. Zak was former bare knuckle champion of the Dales and his family were notorious throughout the village for their rogueish behaviour.
His original family consisted of wife Nellie, sons Butch and Sam and daughter Tina. He had another son, Ben, who was killed in a fight with the local doctor's son, Luke McAllister. He was later found to have a heart defect but this did not stop the Dingles pointing the finger at Luke. Tina had mentioned a brother named Nathan, but he never appeared in the series and was never even acknowledged again.
The family quickly established themselves in the village, and forced Luke's family away, although he stayed and ended up with Tina, much to the annoyance of Zak, who arrived in the village and began to beat Luke, and was only stopped in his tracks when Tina announced her pregnancy. However, it was established she had lied to humiliate him at the altar in revenge for Ben's death, leading to him killing himself in his car and nearly Tina in the process.
As the former head of the Dingle clan, Zak is no stranger to drama. His first wife, Nellie, left him, and he lost two sons, Ben and Butch, in tragic circumstances but Zak soldiers on. He is ever hopeful that the Dingle family can overcome all obstacles. In 2015, he declared son Cain as the new head of the family.
In 1996, many of Zak’s prayers were answered when he met Lisa Clegg. They were instantly smitten and, after a few hiccups, the couple married on 28th January 1998. That Christmas, the couple got an especially welcome Christmas present when Lisa – who had no idea she was pregnant – gave birth to their daughter Belle. In 2000, Zak and Lisa’s marriage was pushed to the limit when Nellie returned. With tensions between them rising, Lisa moved out. Tragedy then struck when Butch was killed in a bus crash. Since Lisa had serviced the bus before it was declared roadworthy, Zak blamed her for the accident and it looked like the marriage was over for good. Zak couldn’t let go that easily and an uneasy truce was declared – largely for the sake of Belle.
In 2001, Zak had the uneasy task of telling violent Cain that he was his real father. After some violent words, the two men accepted the situation and a bond developed between them.
Zak’s health took a turn for the worse when he discovered he had testicular cancer. Zak's illness ensured he got his problems in perspective and his marriage was firmly back on track. Domestic harmony was shattered when his mother Peg came to stay. Zak blamed Peg for the death of his father, Jed, believing she murdered him. When she revealed the truth about Jed deserting them, a truce was declared. When Peg left the village, there was a better understanding between them.
Zak shocked his family when he disappeared to Chile in search of the Dingle fortune. While he was away, Lisa became close to Eddie Hope and it looked like Zak may have lost her for good. Lisa still loved the old scoundrel and they reconciled on his return.
In 2005, Zak was saddened when his son, Sam, left to start a new life with his girlfriend Alice Wilson in Norfolk. Losing Sam made Zak more protective of the other members of his family.
When it was revealed his granddaughter Debbie was having an affair with Andy Sugden , Zak hit the roof – and Andy! The fling came back to haunt them when Debbie gave birth to baby Sarah after concealing her pregnancy from everyone. Like the rest of the family, Zak was delighted that Debbie and her daughter are safe and well, welcoming Sarah into the fold. However, Debbie couldn’t cope with motherhood and despite efforts to get through to her, he was devastated when she gave the baby to her foster mother, Emily Kirk, who subsequently disappeared.
With Debbie gone, Zak had a new crisis to deal with when Sam returned to Emmerdale. He told Zak that he and Alice were expecting a child. Tragedy struck when Alice was diagnosed with cancer. The family rallied round as the couple tried to come to terms with the situation. Under Zak’s guidance, Sam gave Alice the support she needed and the couple were delighted when Samson was born. Their happiness was short lived though, as Alice was told her illness was fatal just as she was preparing to marry Sam. The family were devastated by the diagnosis but Zak was determined to see Sam through the tough times ahead.
Earlier in Zak's history, the family encountered many problems with the then Home Farm owner, Frank Tate. Frank tried to evict the family unsuccessfully and one episode saw the Dingles' celebrate Frank's death with a victory chorus; 'We hate Frank Tate, he tried to evict us, the police came and nicked us, but now, you are dead'. The song was accompanied by them banging their cutlery fiercely on the table whilst at an evening meal. The more recognisable and noted members of the family were also present; Mandy Dingle, Butch Dingle and Sam Dingle.
Zak became friends with Rosemary King. He took her at face value, despite her being devious and manipulative. They got on and she asked him to keep a discreet eye on her son, Grayson, and let her know what he was doing. She hired him as gamekeeper at Home Farm and confided family secrets, knowing she could trust him.
She also bonded with his daughter, Belle, and paid for her to attend private school. That ended when Rosemary confessed to poisoning her daughter-in-law, Perdita Hyde-Sinclair and Zak told her to stay away from him and his daughter, Belle.
In May 2008, Zak resigned as gamekeeper of Home Farm after his nephew Eli broke some advertising material for Matthew King's press launch, at a cost of £1500. Matthew insisted Zak pay for the breakages which he did, with money meant for Belle's school fees. Zak asked Matthew to refund the money, and Matthew agreed, after the insurance company had paid out. Zak told Matthew he couldn't wait but Matthew refused to pay Zak any sooner.
Since then, Zak has been keeping an eye on his family. He was concerned that Sam had developed quite a soft spot for Jo Stiles and annoyed when Sam was beaten up by Andy Sugden. Zak warned Andy if he came anywhere near Sam again, he'd be fighting Zak. After Jo threw Andy out, he and the other Dingles helped Jo run the farm and were shocked by her revelation that Andy had been beating her up for months. When Jo left the village, wanting to reclaim her life, Zak and Lisa got custody of Sarah. When Andy found out, he tried to take Sarah back but Debbie wouldn't let him. Zak told him he was welcome to visit any time, though.
When Cain was viciously attacked in December 2011, Zak seemed very uncomfortable and he later revealed himself as Cain's attacker when he discovered Cain was going to try and get Jai Sharma falsely imprisoned for the crime. Zak also confessed to Lisa and was going to hand himself in, but Cain kept his father's involvement in the attack secret, and retracted his statement against Jai. Zak is racked with guilt over attacking Cain and starts to annoy Lisa by refusing to do anything. He later disappears for the entire day and returns home, oblivious to how worried his family were. He loses his job at Home Farm as he is losing concentration, so he confronts his boss Declan Macey in The Woolpack. Zak begins drinking heavily and his niece Chas is forced to bar him and he is angry when Sam tells him that he is turning into Shadrach. He takes Samson poaching one day and accidentally leaves his phone in the van. Lisa and Sam are frantic with worry. Zak and Samson are later found by Megan Macey, who calls Sam and he arrives to collect Samson and warns Zak to stay away from him. A few weeks later, a scan reveals some abnormalities in Zak's body, he is referred to a consultant to have some more scans. At the appointment with the radiologist, the doctor warns Zak that in the abnormalities could be pancreatic cancer, but also could be a simple curable form of the flu. However, an appointment later reveals that Zak does not have pancreatic cancer. In May 2012, Zak begins to act erratically and becomes paranoid, he is told by a vet that his chickens are healthy but in his paranoia and belief that there is something wrong, he kills them. He later starts believing he has cancer again and talks to a doctor about it, the doctor tells him he does not have cancer but Zak refuses to believe it and tells his family that he has cancer. It later becomes apparent that Zak has suffered a nervous breakdown and is later sectioned.
On Christmas Day 2015, Belle reveals to Lisa that she'd seen Zak having an affair with their lodger Joanie Wright. Lisa is heartbroken by the news, and her and Zak separate. This separation effectively severs Zak's ties to the rest of the family, who convene at Wishing Well Cottage and decide to "excommunicate" Zak from the Dingles. Zak and Joanie then move in with the biological grandmother of Joanie's adoptive grandson Kyle, Kerry.
Early in 2016, Zak tries to regain the attention of his estranged family, especially after they all begin to act rather out of character. Zak becomes determined to know what's going on, and he pesters Sam and Belle in the village shop to tell him the secret they're supposedly hiding. The two initially try to keep it together, but, pushed to her limit, Belle blurts out that Aaron was raped as a child by his father Gordon. Much like the rest of the family, Zak is devastated by the news, and Joanie begins to question his loyalties.
"Fancy that. A party, and no-one thought to invite us." (First line)
"Lunatic, is it? Yeah? Well is this mad enough for ya? Eh?" (before setting Cain Dingle's caravan alight)
Zak: "Yeah, well, what you did today was not make it worse by causing more trouble! I remember what it's like, you know. Feeling indestructible. When I were younger I used to think I could take on the whole world! And that is always when things went wrong. Sometimes you just have to step back! And you're right. You don't need me talking to you about being responsible for the family, I know what you do for 'em. And I've seen how, how they respect you for it. I'm old, Cain. I'm not gonna be around forever. And I'd say that I needed you to step up to be head of this family. But the truth is, y'already are. Y'have been for a while now."
Cain: "What, head of the Dingles?"
Zak: "Aye, lad. Whether you like it or not. That is exactly who you are now. You are head of the Dingles." (Zak handing over headship of the Dingles to Cain after talking him out of killing Robert Sugden)