- "Manners Maketh Man, Do you know what that means? Well, let me teach you a lesson."
- ― Harry before fighting in the Black Prince Pub
Not much is known about Harry's early life, although it was stated in Kingsman: The Golden Circle that he wanted to become a lepidopterist, but instead chose to become an officer in the British Army. After serving in the military for some time, he was recruited into Kingsman.
Harry and his unit were conducting a raid in the Middle East when their captive pulled a grenade. Harry's candidate for the position of Lancelot quickly jumped on the grenade, saving the unit at the cost of his life, but he still felt guilty for not properly searching the man. The other agent present was given the position with the man's death. He gave a bravery medal to the deceased agent's widow and his son, Gary "Eggsy" Unwin, telling them that if they ever need help, they should call the phone number on the back of the medal and deliver a coded message.
Seventeen years later, Eggsy called the number and used the code to get himself out of trouble after having been arrested for stealing a car and driving dangerously. Harry saw some Kingsman potential with the recent death of Lancelot, and they went to a bar where Eggsy had gotten in trouble with some of his stepfather's goons.
They tried to intimidate Harry into leaving, but instead he simply locked the front doors before starting a brawl that left all of the other men in the bar incapacitated. Finishing his drink, he apologized to Eggsy about it, saying that he had some pent up anger after the death of one of his associates, and was about to wipe his memory of the event when Eggsy said that he could keep a secret. Willing to test him, he placed a bug on his shoulder without him noticing before letting him leave.
The Introduction of Kingsman
True to his word, Eggsy didn't say anything when his stepfather was beating him to know who was in the bar with him, and before anything bad happened Harry intervened through the bug, asking for Eggsy to go to the Kingsman tailor shop to meet him there. Harry offers him a chance to become a Kingsman agent, taking him to the Kingsman Mansion for training and testing.
The Case of James Arnold & Dinner with Valentine
Meanwhile, Harry was also working on the case of Professor James Arnold, who had been kidnapped a short time ago and was the case on which the former agent Lancelot was working at the time of his death. However, Arnold was seen in public a few short days earlier. Finding Professor Arnold, he tried to interrogate him about his kidnapping, only for a chip in his head to explode, killing him and throwing Harry in a deep coma.
Upon his awakening, he took a fake identity to meet Valentine himself, posing as a billionaire. The two met over a McDonalds meal, discussing Valentine's views. However, Valentine suspected him to be a secret agent, and his drink had as a tracking device in it.
Eggsy's Final Test
Back in London, Harry takes Eggsy to the Kingsman tailor to have his suit measures taken, only to run into Valentine again, who was having a suit made for him as well. Still posing as a billionaire to him, he suggested he buy a top hat to go with the suit. The hat would have a listening device in it, allowing them to discover more about his plans.
Meanwhile, Eggsy was on his last Kingsman test: shooting his dog. He did not, which when he met Harry again made him very disappointed in him, revealing that the gun he was handed was filled with blanks. The two were not able to reconcile, as Harry had to leave to track down Valentine. Before leaving, he told Eggsy to stay and that they'd finish it when he'd return. Harry was being the father figure at this time.
Following Valentine's trail to Kentucky, he assisted to a bigoted and hate-filled speech in a church. Not seeing Valentine anywhere, he was about to leave when Valentine activated his SIM cards making everyone, Harry included, go berserk and turning the church in a bloody battlefield. Harry personally killed several of the churchgoers and was the last man standing by the end. Remorseful over having killed so many people, he exited the church where he met Richmond Valentine face to face with Gazelle and two armed men.
Whilst at gun-point, Valentine joked about how their situation was similar to that of an old spy movie, before shooting Harry in the eye, where he was presumed dead.
Unbeknownst to Valentine, Eggsy, Merlin, Arthur, or anyone else, the Statesman (the Kingsman's American cousins) noticed the signal of Valentines chips activating and sent Agent Tequila and Ginger Ale in a helicopter to investigate the situation. The two agents found Harry shortly after Valentine had left, and quickly applied alpha-gel to repair his damaged brain tissue, which saved his life. After investigating the church, Tequila and Ginger brought him with them back to the Statesman headquarters.
As a side effect from the bullet wound and the alpha-gel, Harry suffered from amnesia and believed himself to be a lepidopterist.
Reunion with Eggsy and Merlin and Regaining Memory
Harry remained in Statesman custody for a year, with the agency having no idea who he was and thus how to restore his memories. When Eggsy and Merlin travelled to the Statesman headquarters after Kingsman was destroyed by the Golden Circle, they were shocked to discover that the former Galahad was still alive, and were devastated to learn that he did not recognize them. Merlin and Ginger attempted to help Harry regain his memories by making him remember a traumatic event in his past, but their attempt by filling his cell with water and nearly drowning him proved ineffective. It wasn't until Eggsy bought a terrier which resembled Hart's dog, Mr. Pickle, gave it to Hart and threatened to shoot it did Hart's memories come back to him.
Harry was given all the essential Kingsman attire. His suit, watch, umbrella and modified glasses with a blacked out lense to accommodate Harry’s lost eye. Harry was once again a Kingsman agent and Galahad. When a disgruntled American threatened Harry, he attempted to fight the group but was quickly overcome by their sheer strength. Saved by Agent Whiskey, Harry thought he has been fixed but was told that even though they had brought back his memories, his orientation would return in time and that his butterfly hallucinations would subside.
However, some of the symptoms of his amnesia still remained, like loss of coordination during a fight scene in a bar, attempting to start a brawl with a bunch of men just like in the last film. Hart gets punched in the face by one of the men while Jack Daniels caught the mug that Hart attempted, with his umbrella, to knockout one of the men with. Daniels then helps Hart in starting a brawl with the men, knocking them all unconscious with minor injuries.
Italy and Shooting Agent Whiskey
Hart goes with Eggsy and Jack Daniels to Italy where Poppy's antidote supply for her drugs are located. Harry takes over the control room once he knocks out a guard unconscious. The trio leave the factory and head for a cabin once Eggsy and Whiskey had retrieved a bottle of the antidote from the factory. Once there, a gunfight ensues between a bunch of Poppy's soldiers. During the gunfight, Harry shoots Whiskey in the head, as he suspects that Whiskey is playing both sides, but Eggsy saves him with the same alpha-gel used to save Harry.
When Poppy Adams announced that she had laced every recreational drug in the world with a virus that caused a blue rash that would lead to mania, paralysis and then death. Eggsy using the tracker he had placed in the girlfriend of former Kingsman recruit Charlie Hesketh lead them to a secret factory in Italy so they could acquire a sample of antidote to replicate and distribute worldwide to save lives. Under the advice of Eggsy and Whiskey, Harry operated the sky lift to allow his fellow agents a chance to escape with the drug. When the escape was thwarted by agents of The Golden Circle, Harry rendezvoused with Eggsy and Whiskey in a cabin. Harry, who became suspicious of Whiskey believed he was working for both sides, a conclusion he came to when Whiskey destroyed the vial of antidote, shot the Statesman agent in the head. Harry quickly dealt with the Golden Circle agents using an explosive bottle of cologne. Eggsy became angry at Harry, believing he was still under the effects of his recent trauma chastised Harry whilst saving the Statesman agent's life using Alpha Gel.
Attack at Poppy Land
Discovering the location of Poppy’s hideout in Cambodia, Eggsy, Harry and Merlin flew there to steal the device that could help release the drones that dispensed the antidote. Eggsy, Harry and Merlin made their way through the jungle towards Poppy Land. Eggsy inadvertently stepped on a land mine. Merlin froze the trigger for a split second allowing Eggsy and Harry to move away whilst at the cost of Merlin's own life. Harry, realizing that this was the last time he would see his friend, thanked him for his service, and stated how it was an honour. Merlin sacrificed himself whilst taking the perimeter guards with him thus allowing Harry and Eggsy to move forward with the mission.
Harry and Eggsy stormed the base, eliminating any Golden Circle agents in their path. After they had dealt with all the agents in the courtyard, they entered the diner. Charlie quickly escaped with the case holding the drone activation device. Harry ordered Eggsy to give chase to Charlie whilst he pressed Poppy for the activation code. Poppy quickly set her robotic dogs on Harry. Harry quickly subdued one of the mechanical beasts with the help of Elton John using bowling balls. Harry managed to subdue the other using the molten gold tattoo machine. After the fight, Eggsy and Harry enter the diner again to face Poppy. Harry quickly incapacitated Poppy whilst Eggsy injected her with a dose of heroin laced with a more potent strain of her virus. Poppy gave the activation code before quickly succumbing to the effects of the drug.
With the mission a success, the two agents prepared to release the drones to the world but were stopped by Agent Whiskey, who revealed he had his own hidden agenda: to stop all drug users as recompense for the death of his wife and unborn son at the hands of two drugged individuals who tried to rob a store. A grueling battle between them quickly ensued throughout the diner ending with Harry and Eggsy forcing Whiskey into the meat grinder. They quickly entered the code and saved the lives of millions of people.
Harry and Eggsy were thanked by Statesman and both agents were offered the role of Whiskey which they both declined. Statesman head Champ revealed they had acquired a distillery in Scotland and would help rebuild Kingsman effectively making them liquor sellers as well as tailors with the help of Statesman. The Kingsman tailor shop was open once again. Harry attended the wedding of Eggsy and Princess Tilde, proud that his protégé had achieved so much, and repeated a saying made by one of the Kingsman founders.
"This is not the end, this is not even the beginning of the end, but merely the end of the beginning."
- Kingsman - Teammates
- Statesman - Saviours
- Michelle Unwin
- Princess Tilde
- Elton John
- Jack Daniels/Whiskey - Temporary Ally and Victim
- Richmond Valentine - Killer
- The Golden Circle
- Harry is right-handed, as he explains to Eggsy, that all Kingsman wear their rings on which ever hand is dominant, and he can be seen wearing his ring on his right hand, thus making him right-handed.
- The actor portraying Harry, Colin Firth, was said to do 80% of the stunts in The Secret Service himself. 6 months prior to the filming, Firth had trainers helping him with the fight choreographies and activities.
- Harry's comic book counterpart is Jack London, who in the comic-books is actually the uncle of Eggsy.
- Harry seems to be a fan of Elton John and his music, as after he asked Elton that if he saved the world if he could have two tickets to Elton's next concert.
- Colin Firth himself said that we don't know anything about Harry and that he might not be straight.