Brian Braddock was a student assistant at the Darkmoor Research Centre when the criminal Reaver attacked the facility to steal its secrets. Attempting to escape, Braddock ran his motorcycle off a cliff and lay near death. In a vision, Merlin the Magician and the Goddess of the Northern Skies appeared to him and bade him choose one of the mystic objects before him: the Amulet of Right or the Sword of Might. Braddock chose the amulet and was bombarded with mystical energy that granted him superhuman strength and stamina. The patron spirits decreed that Braddock would be Britain's champion, and gifted him with a mystic star-scepter to enhance his fighting skills.
Through Merlin's tutelage, Brian learned the truth about his family's extra-dimensional origins. He learned of his metaphysical connection to the land and people of Otherworld -- a glorious kingdom positioned at the nexus of reality, where science and sorcery exist as one. To safeguard the infinite realities from evil, Merlin had founded an elite cadre of heroes, the Captain Britain Corps. No greater force for good existed in the Omniverse, and no greater hero bore the Corps' legendary standard than Brian's father, Sir James Braddock. Scientist, warrior, philosopher, strategist -- these attributes made Sir James the ideal candidate to embark upon the sacred mission that would shape the future: the quest to sire a savior; to father a king. A genetically compatible mate -- Brian's mother, Elizabeth -- was selected from our Earth, 616.
Eventually, Braddock stepped down from the role -- allowing his twin sister, Betsy, to take up the mantle. But Betsy was unprepared to serve as Captain Britain, and lost her eyes in a battle with Slaymaster. Braddock heard his twin's pain through her telepathy and the special bond they share, and rushed back to fight Slaymaster -- whom he killed. Resuming his career as Captain Britain, Braddock joined with the shapeshifter Meggan, Shadowcat, Nightcrawler, Phoenix II to form Excalibur -- England's premier team of heroes.
Although continuing his affiliation with Excalibur, Braddock quit the hero's life for a second time to concentrate on science. Later, he and Meggan took a break from the team. During their time away, Braddock proposed.
Subsequently, Braddock returned to action in a newly refurbished costume, apparently having reconciled his scientific and super-heroic sides. But during a battle with the Dragons of the Crimson Dawn, Braddock expended all his energy to stop a dimensional portal from opening. He has not regained his powers.
Braddock again left the Excalibur, but returned to fulfill his dream of marrying Meggan. During the ceremony on Otherworld, the rest of the team decided to return to the States. The team disbanded. In the wake of Excalibur's dissolution, Brain and Meggan at last were afforded the opportunity to lead "normal" lives. But their peace was shattered when Brian learned that a seemingly insane Roma had decimated Otherworld in a quest to dominate all reality. The Captain Britain Corps rallied to repel Roma's hordes, but even its greatest heroes proved no match for the monsters and their malevolent mistress. Leading a small squad of warriors, Captain Britain rescued Roma from the thrall of the rogue android called Mastermind, a hyper-sentient techno-organic super-computer created by Brian's father. Reclaiming the Sword of Might, Captain Britain united the talismans of power. Brian had finally unleashed his divine spark and fulfilled his destiny as the true monarch of Otherworld and protector of the Omniverse.