Jamie was the eldest son of Dr. James Braddock and Lady Elizabeth Braddock. He was nearly 10 years older than his siblings and always felt excluded from the twins, who were very close.
After he grew up, he made his name as a financial genius and was a successful race car driver as well. Braddock Industries flourished under Jamie and the handsome, successful man was a popular figure. He was targeted by Dr. Synne who caused him to have a car accident, and then possessed Betsy to attack both her brothers. Jamie became aware of his brother's secret identity as Captain Britain and assisted him on several occasions. In his spare time Jamie started to make illegal bets and his debts piled up. This eventually led to the disappearance and presumed death of three of his friends when came across the First Fallen while being threatened by those Jamie had come to owe money to. His friends became the Foursaken while Jamie escaped that fate, but was still captured and tortured for his debts.
Soon Jamie became involved with various illegal activities to pay his debts. Starting out with minor crimes, he eventually became involved with robbery, murder, and slave-trade in Africa. Jamie was kidnapped by Doctor Crocodile, an African scientist and sorcerer who wanted to punish Jamie for his crimes. He made Jamie call his brother Brian, thinking that Brian was involved with Jamie's crimes as well. Crocodile's witch doctor created a hallucination for Brian so that he and Crocodile could observe Brian's reaction to the crimes Jamie had committed. Convinced that Brian was innocent, Crocodile told Brian about Jamie. Brian was shocked and furious, even trying to kill his brother. Brian left Jamie in the hands of Doctor Crocodile and returned home.
Doctor Crocodile's treatments turned Jamie insane. Jamie now believed that the world around him was just a dream that he was having and his reality-warping powers awoke. Sat-Yr-9 under the stolen identity of Courtney Ross hired Technet to free Jamie, aware of his powers from her own world's Jamie. Crocodile then revealed Jamie's crimes to Technet as well and they turned on Jamie, but he defeated them and erased their memories of these events. Jamie turned Doctor Crocodile into a real, baby crocodile and left with Sat-Yr-9.
Sat-Yr-9 used Jamie's reality warping powers to turn the London criminal Vixen into a dog and her assistant Nigel Frobisher into a duplicate of Vixen. This allowed her to take over Vixen's criminal empire. They used their resources to ambush Excalibur, a superhero team Brian had joined. During the ambush Jamie Braddock killed Alysande Stuart. Jamie was defeated when Brian's girlfriend Meggan turned out to be immune to his powers and his sister, Elizabeth, now the X-Man Psylocke, used her telepathic knife to knock him out. Sat-Yr-9 managed to take Jamie's unconscious body with her and they escaped. Jamie stayed in a coma for years, apparently abandoned by Sat-Yr-9 and taken to Muir Island for treatment.
Jamie was believed to have been killed during Mystique's bombing of Muir Island, but in reality he survived. Jamie was briefly seen at Braddock Manor by Rachel Summers. Mad Jim Jaspers and the Fury also mysteriously reappeared soon after. Jamie again appeared to assist his siblings during the House of M.
When he appeared again to the X-Men he revealed that he was responsible for Psylocke's resurrection. He claimed she was needed to help him battle the First Fallen and the Foursaken. The Foursaken wished Jamie to join them as he was supposed to be their fourth member. At the last moment Jamie appeared to be unwilling to use his sister against the First Fallen and instead sent her and the other X-Men back to New York while he dealt with it himself.
The Trial of Fantomex
Some time later, Jamie joined the Captain Britain Corps and helped them during the attack on the Otherworld. However, the attacker turned out to be an older version of Jamie who had been possessed by the Horoam'ce, the devil goat who wished to enter the Starlight Citadel and seize the Multiverse. To stop him, Psylocke had to take control of her brother Brian, who could not bring himself to kill his brother, and used him to snap Jamie's neck, erasing the older version from existence.
Jamie later came back to life through unknown means and began dabbling in dark magic. While in London, he chased after Black Widow for the Space Stone in her possession, using brainwashed children and loyal followers. When Black Widow confronted him in his hideout, he had an asp from the Sixth Dimension bite her and inject a venom that would slowly kill her. After Widow took out Jamie's followers, she teleported him into a wall. Jamie bled out, and more asps emerged from his blood since his body was holding them back. With help of the wizard Merlin, Widow dealt with the asps, freed the children under Jamie's control, and was saved from the asp venom. He later was reported dead by unknown means.
The Return of the King
Due to Jamie's familial connections to Otherworld, he was chosen for Apocalypse's plan to unite Otherworld and Krakoa by taking the mantle of Avalon's ruler, following his plans for succession. Due to their brother, Brian, being captured and tortured, relieved of his Captain Britain duties and under Morgan Le Fay's control as Captain Avalon, Betsy took Brian's Amulet of Right and took up the mantle of Captain Britain.
With her new status, Betsy was able to challenge Morgan's champion, Brian, for right of rulership of Avalon. With Betsy having the upper-hand with her mutant powers, combined with those of the Captain Britain mantle, she reluctantly killed him and won the battle. Jamie then revived Brian and cleared him of the mind control he had been under, all while becoming Avalon's new King. Due to his new status as royalty, he served as an ally to Krakoa, giving them access to the magical library and country of Avalon through a special Krakoan Gateway for Krakoan citizens, namely Apocalypse and Exodus.
The New Captain Britain(s)
Bored with sitting upon the throne, he used his powers of reality manipulation to bend parts of Avalon to his will and more to his liking, mainly for joking around. Moving on from joking to malevolence, he conjured ideas for war against the rest of Otherworld. He started to invade the lives of Excalibur by creating pocket realities and duplicates of each member as their own versions of Captain Britain, using this version of Excalibur to replace the destroyed Captain Britain Corps.
The manipulation of reality hadn't gone unnoticed, Saturnyne felt the incursions that Jamie created and declared war with the new Captain Britain Corps as he planned, although his plan was foiled by her and Excalibur and the new corps was jailed.
Before the beginning of the X of Swords tournament held by Saturnyne, Jamie and his family were invited to stay at Saturnyne's castle for preparations for the upcoming battles she would dictate. With the "Captain Britain Corps" escaping captivity, they decided to attack a sleeping Jamie for his wrongdoings. They were woefully unprepared, as Jamie pulled on some quantum strings when awoken by their battle cry and killed the Captain Britain version of Jubilee.
While further organizing this tournament, Saturnyne decreed a set of challenges that would be issued against the warriors from Krakoa and Amenth that would let either side take claim of the other's land. Due to this, the Hellions tried to cheat and kill the other team. They travelled to Avalon to meet with Jamie for safe passage though Avalon and Otherworld, with Sinister promising Jamie his cape and a favor in the form of one clone of his choosing, with Jamie giving Sinister a "gift" of one of the finest ponies in the realm.
During one of the challenges, Jamie was a spectator to Betsy's fight against Isca in a sword duel, but she ended up losing by being shattered into glass-like pieces, apparently dying. Although saddened by the loss, he had placed a large bet on Isca winning.
The Quest For Betsy
Missing his sister, and her not being eligible for resurrection due to the updated resurrection protocols of The Five, he thought about using his powers to either find or revive her, only to be met by opposition from Brian and his family. Instead, Jamie called in his favour with Sinister to make a new Betsy, exactly like the old one. Later on, the husk clone was taken over by the incorporeal mutant Malice who tried to take her place.
He was later recruited by Magneto during the Hellfire Gala, along with many other Omega Level Mutants, to terraform Mars so it could be gifted to Arakko as their new home-world. He also created a copy of the Peak VII for the the sake of communication between Krakoa and Arakko and the newly reformed planets' protection.
- Reality Manipulation [Quantum]: Jamie sees the world as invisible string constructs, which he can pull (or just think about what he wants to do) and transform reality. He can only manipulate dense forms (phased beings have some level of resistance); formerly he needed to be close enough to touch the "cosmic filaments" things they were composed of. His range and power has grown, based on how Krakoan resurrections increase a mutants potential, and recent events in his siblings' lives. He can now smilingly create without any of his old restrictions.
- Temporal Manipulation: Jamie was able to spilt his own timeline into many, making the members of Excalibur a Captain Britain in the newly created pocket realities. With each incursion he makes, they can branch off into however many realities he wants, with him in complete control.
- Creation: Jamie can create something or someone entirely new with a simple thought such as a psionic butterfly or a space port for Mars.
- Duplication: Jamie is able to create copies of other people, places, things, and even timelines. Even furthermore, he can simply create another reality and bring whatever he wants to his own.
- Power Manipulation: Jamie can bestow, augment, or take away the powers of another, or himself.
- Matter Manipulation
- Healing: Jamie has the power to heal the wounds of himself and others.
- Resurrection: Jamie is able to raise the dead, as he did with his brother Brian.
- Mind Control: Jamie is able to put others under his control or completely make new memories for others.
- Illusion Casting: Jamie can alter the perceptions of others.
Sorcery: After his resurrection, Jamie demonstrated magic powers, including the summoning of extra dimensional creatures and mind control over others. His magical abilities are stronger in Otherworld due to it being a place of ideas and the greater flow of magic.
Superhuman Stamina: Jamie appears to have superhuman stamina as he survived being stabbed with a knife and even having his legs severed at the knee. He also "birthed" a replica of the Peak VII as it ripped out his stomach.
- Jamie presumably had knowledge in the magical dark arts, including spell casting and incantations.
- Jamie's power is vastly stronger in Otherworld due to Otherworld being a place where ideas and fantasy being easily influenced and malleable, making bending and pulling the strings of reality all the more easier for him.
- Jamie has a fondness for capes, not unlike Mr. Sinister and Magneto. Rather than making his own cape with his powers, he barters for others e.g Mr. Sinister and Magneto.
- 56 appearance(s) of James Braddock Jr. (Earth-616)
- 5 appearance(s) in handbook(s) of James Braddock Jr. (Earth-616)
- 15 minor appearance(s) of James Braddock Jr. (Earth-616)
- 14 mention(s) of James Braddock Jr. (Earth-616)
- 4 mention(s) in handbook(s) of James Braddock Jr. (Earth-616)
- 37 image(s) of James Braddock Jr. (Earth-616)
- 5 quotation(s) by or about James Braddock Jr. (Earth-616)