Young Brock Rumlow led the Savage Crims gang on New York's lower east side. After he brutalized fifteen year old Rachel Leighton, two of her brothers assaulted Brock and he killed them. Rumlow fled, entering the Taskmaster's school for criminals, and within three years he became an instructor there under the name Bingo Brock.
As a mercenary, he enlisted with the communist Red Skull (Albert Malik) in Algeria, serving him as "Frag" until he was sent to invade Arnim Zola's Switzerland chateau. Ultimately the only team member to survive the assault, Rumlow met and impressed the Nazi Red Skull (Johann Schmidt), who accepted Brock’s services, codenaming him "Crossbones".
Sent to retrieve the five Bloodstone fragments of Ulysses Bloodstone, Crossbones shadowed Baron Helmut Zemo's search for them. While Zemo battled Captain America, Crossbones knocked out Captain America's pilot, John Jameson, and stole two Bloodstone fragments; when he got near the other three, the five combined to re-animate Baron Heinrich Zemo's corpse under control of the alien Hellfire Helix. Unobserved, Crossbones destroyed the Helix (worn on the corpse's forehead) with a crossbow bolt.
Brock then kidnapped Captain America's ally Diamondback (whom he recognized as Rachel Leighton), using her as bait to trap Captain America in Madripoor. Cap trapped him on a bomb in an abandoned building; but when the Skull learned of Crossbones involvement with the Captain, he ordered Crossbones to flee and he escaped just in time. Crossbones was then ordered to work with the Controller-hypnotize Namor to attack Captain America. The Red Skull then ordered Crossbones to help a group of prisoners escape from the Vault.
Crossbones recruited the Controller and Voice to serve the Skull, led the Skeleton Crew against the Hellfire Club’s Selene, and, using psychic Tristram Micawber, located the Skull after Magneto had kidnapped him. Crossbones an the crew trap Cap and Diamondback in the Skull-House.
Crossbones and the Skeleton Crew relaxed in their posh Washington, D.C. exclusive club. The party is spoiled when the Skull discovered someone has attacked Arnim Zola's compound and destroyed all of the Red Skull body double clones. Crossbones led the Skeleton Crew when they were captured by the Schutz Heiliggruppe (Blitzkrieg, Hauptmann Deutschland, Zeitgeist); afterwards Arnim Zola rescued them. The team were almost arrested and taken in custody by the Avengers. The Red Skull faked the assassination of himself, Mother Night, and Crossbones. The Red Skull finally fired Crossbones for questioning the Skull's decision to ally with the Viper.
In New York, Crossbones kidnapped Rachel to brainwash and torture her by abusing her repeatedly and forcing her through a rigid combat training routine. He had her call the Avengers Mansion to tell Cap not to look for her. Black Widow investigates Diamondback's phone call but finds nothing while Crossbones imprisons Diamondback in Magneto's fallout shelter. Crossbones forced Diamondback to steal Captain America's Super-Soldier Serum treated blood from Avengers Mansion.
Crossbones returned to the employ of the Red Skull and the Skeleton Crew. The new leader, Cutthroat (Diamondback's brother Daniel), plotted Crossbones' murder, Mother Night warned Brock, who slit Cutthroat's jugular. Diamondback escaped, summoning Captain America and the Falcon to capture the Skull’s operatives; Crossbones was imprisoned, but eventually convinced officials he was rehabilitating, partly by defeating the terrorist cell "Fortress" when they invaded a Denver hospital. Exploiting his jailers' gullibility, Crossbones escaped, and was hired by Hydra to bomb New York's embassy row alongside the Absorbing Man, but the pair was stopped by Captain America. Betrayed by Hydra, Crossbones fled, wreaking vengeance on his bosses. 
The Death of Captain America
The Skull promptly rehired him, and he was aiding in re-powering a Cosmic Cube when Aleksander Lukin’s Winter Soldier assassinated the Red Skull and stole the Cube. Lukin anonymously blamed Captain America for the Skull’s death, but Crossbones soon realized the truth and began hunting Lukin. He continued to go through with the Skull's plans, running an offshoot branch of AIM, and kidnapping and brainwashing Sin (Synthia Schmidt), the daughter of the Red Skull. The Red Skull eventually proved to have used the Cosmic Cube while dying to transfer his mind into Lukin's body, and he recruited Crossbones and Sin back into his service.
During the super hero Civil War, he orchestrated the assassination of his longtime arch-foe, Captain America. The plan involved Sharon Carter of S.H.I.E.L.D., one of Cap's closest allies, being brainwashed by Doctor Faustus into shooting him at close range. This was supplemented by shots fired by a sniper, specifically Crossbones. He was soon captured by S.H.I.E.L.D.
Captain America: Reborn
Crossbones and Sin escaped from a H.A.M.M.E.R. holding facility in Colorado. Norman Osborn approached the duo for a mission. Working with the Red Skull again, they attempted to transfer the Skull's consciousness into the preserved body of Steve Rogers. Instead, the Skull was apparently deleted and the original Captain America was alive again.
Luke Cage's Thunderbolts
He was recruited to be a new member of the Thunderbolts led by Luke Cage, and was participating in the assaults on the New York fortress of the Hand. While on a mission in New Guinea he breathed in the Terrigen Mist and gained energy blast powers. While on a mission with the Avengers, Brock, Juggernaut and Ghost threw off the teleportation signal and ended up in a different dimension together with the Avengers. Brock attempted to kill Captain America but he was thrown into a strange pool of water that reversed the effects of the Terrigen Mist and cost him his powers. After the mission he was taken off the Thunderbolts and returned to incarceration.
Working For the Man
During his time in custody, Crossbones was sent to an isolated island that was hit by a terrible virus outbreak. Brock was sent in with one objective: rescue the one person who may possess the resistance to the virus. Heavily armed, Brock eventually meets a camp of survivors on the island. It turns out the individual is just a boy, and Brock betrays the survivors by letting the monsters (who are essentially werewolves) into their base. Brock battles a few, snapping their necks and withstanding a handful of claw attacks before reaching his evacuation helicopter with the child. But, Brock betrays his employers by pushing the boy out of the helicopter, sending him falling to his death.
During the Serpent War, one of the mystical hammers of the Worthy fell into the Raft, choosing Juggernaut as its wielder. Marko's transformation into Kuurth caused massive damage to the Raft, which led to a breakout. Crossbones seized his chance to escape, and worked with Man Mountain Mario to achieve his goal, and repaid Mario by murdering him.
When Sin was in search of the missing hammers of the Worthy, Crossbones helped her by globe-trotting to find these items. His journey took him to French waters, where he confronted Namor, and New York City, where he fought against Luke Cage.
Ends of the Earth
While hunting Hell-Marks through the country, Crossbones killed and skinned one of the many copies of Daimon Hellstrom. Along with the D.O.A., Crossbones targeted Mania as she had received the Hell-Mark that was once of Venom along with her symbiote. After battling Venom and Mania, who had used the demons that Master Mayhem had summoned to attack them, he and some members of the D.O.A. vanished.
All-New Captain America
When Steve Rogers' son Ian Zola and All-New Captain America Sam Wilson were teleported from Ecuador to the new Hydra's main basement in Bagalia, Crossbones was there with several other new Hydra members, including their leader, Baron Zemo. Sam and Ian engaged a war with them: Cap took the mysterious kid they saved in Ecuador, running away from the basement, with Brock following them. The kid was revealed to be an Hydra agent, an Inhuman "created" by the Terrigen Mist with the Mist "Infection Power" in his blood. Cap, wounded, started a fight with Crossbones, but Wilson was saved by an undercover Misty Knight. He was later defeated by Sam Wilson when he attacked a Hydra base located in Florida.
Crossbones was an inmate of Pleasant Hill, a gated community established by S.H.I.E.L.D. When Steve Rogers was at the Pleasant Hill Bowling Alley trying to reason with Kobik, Crossbones attacked Rogers. Before Crossbones could kill Rogers, Kobik used her powers to de-age Rogers back to his physical prime, which allowed him to defeat Crossbones. In the aftermath of the events at Pleasant Hill, Crossbones founded a new version of Hydra with the Red Skull and Sin.
Enhanced Physical Conditioning: Crossbones was augmented by unknown enhancements. He possesses strength, durability, reflexes, and stamina superior to those of normal humans. The unknown enhancements have also augmented his body mass to a great extent. Daredevil has compared Crossbones' physical condition to Captain America's. Rumlow additionally possesses an enhanced metabolism.
- Peak Human Strength: Crossbones' physical strength is enhanced to the peak of human potential, enabling him to lift up to 800 lbs. He is strong enough to easily break a mutated Hazer Citizens' neck.
- Peak Human Durability: Crossbones can withstand to physical injury than normal humans. He withstand getting smash through a solid brick wall by Winter Soldier.
- Peak Human Speed: Crossbones is able to move at speeds faster than the Olympic-class runners, enabling him to run at speeds of 32-36 mph.
- Peak Human Stamina: Crossbones' musculature produced less fatigue toxins during his physical activity. He could exert himself at peak capacity for up to one hour before showing any signs of fatigue.
- Peak Human Reflexes: Despite of his bulk size, Crossbones' reaction speed is faster than the average person. He was able to dodge multiple gunshots from one of Kingpin's men at mid-range.
Master Martial Artist: Crossbones is one of the world's best hand-to-hand combatants, with extensive training in street-fighting, military combat, and various forms of martial arts. He has trained extensively with the Taskmaster to the point where he was actually made an instructor at the Taskmaster's school for criminals.
Expert Marksman: Crossbones is also a superior marksman with guns, crossbows, and throwing knives.
Interrogation/Torture: He also has some experience with torture and brainwashing, having effectively "reprogrammed" Sin and nearly so with Diamondback.
Expert Pilot: He is also an expert pilot.
Psychopath: Crossbones is often said to be a psychopath.
Carries various communications devices, one of which is mounted in one of his gauntlets.
His weaponry includes various firearms, a collapsible crossbow, a wrist spike, spring-loaded stiletto blades in his gauntlets, various explosives and poisoned knives.
Usually the Red Skull's private jet or helicopter.
- Crossbones was involved in the battle between the Marvel and DC Universe.
- 167 appearance(s) of Brock Rumlow (Earth-616)
- 11 minor appearance(s) of Brock Rumlow (Earth-616)
- 10 mention(s) of Brock Rumlow (Earth-616)
- 70 image(s) of Brock Rumlow (Earth-616)
- 13 quotation(s) by or about Brock Rumlow (Earth-616)
- 7 victim(s) killed by Brock Rumlow (Earth-616)
- 1 item(s) used/owned by Brock Rumlow (Earth-616)
Links and References
- Brock Rumlow (Earth-616) on Marvel.com
- Brock Rumlow (Earth-616) on Wikipedia.org
- Brock Rumlow (Earth-616) at Comic Vine