Young Brock Rumlow led the Savage Crims gang on
New York City's
Lower East Side. After he brutalized fifteen-year-old
Rachel Leighton, two of her brothers assaulted Rumlow 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, Rumlow enlisted with
Albert Malik, the
communist Red Skull, 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 Johann Shmidt, the original Nazi Red Skull, who accepted Brock’s services and codenamed him "Crossbones". The true Red Skull sent Crossbones to observe
Baron Helmut Zemo's progress acquiring the
Bloodstone fragments and to obtain them. He stowed aboard
Captain America's flagship, and entered Zemo's ship to steal the Bloodstone fragments. He overpowered Leighton, now the hero Diamondback, and shot a crossbow bolt that coupled with
Captain America's shield. Crossbones was forced to shatter the Bloodstone fragments when the alien entity known as the Hellfire Helix used it to take control of
Baron Heinrich Zemo's body; the destruction of the Bloodstone discorporated the Hellfire Helix. Knowing that his employer would be infuriated by the Bloodstone's loss, Crossbones kidnapped Diamondback to
Madripoor as bait for Captain America. He challenged Captain America to retrieve Diamondback, but the Captain defeated him, although Diamondback escaped, and the Red Skull ordered Crossbones to desist and return to headquarters. The Red Skull then ordered him to retrieve the
Controller after the Controller's breakout from the
Vault. With the
Machinesmith, Crossbones investigated the Red Skull's disappearance. Crossbones assembled the
Skeleton Crew from the Red Skull's henchmen and led them on a search for the Red Skull, who had been missing since Magneto imprisoned him in an underground bunker. Alongside the Skeleton Crew, he battled the Schutzheilligruppe in an attempt to rescue the Red Skull but was captured. Crossbones was eventually fired for questioning the Red Skull's alliance with
Viper. Desperate to regain his position as leader of the Skeleton Crew, Crossbones kidnapped Diamondback, imprisoning her in an abandoned subway station and forced into a brutal regime of combat training. Crossbones believed that he had brainwashed Diamondback into betraying Captain America, but Diamondback was actually laying a trap for Crossbones. Diamondback stole samples of Captain America's blood from the Avengers' mansion, then accompanied Crossbones to the Red Skull's mountain fortress. The two were captured and imprisoned, and the Red Skull rehired Crossbones on a temporary basis. After he escaped from prison, Crossbones became a mercenary and assassin for a number of organizations, until he was rehired by the Red Skull who was later apparently assassinated by
the Winter Soldier. Crossbones and his new lover,
Synthia Schmidt (the Red Skull's daughter), began hunting
Aleksander Lukin, the Winter Soldier's commander. Following the "
Civil War" storyline, Captain America's Anti-Registration heroes surrender to
Iron Man's Pro-Registration heroes. While being led from Federal Courthouse, Captain America is shot in the shoulder by Crossbones under the Red Skull's orders. Crossbones tries to escape in a helicopter, but is thwarted by
Falcon and the
Winter Soldier. At the start of the "
Heroic Age" event, Crossbones has become a member of the new Thunderbolts team formed in the aftermath of
Norman Osborn's
siege of Asgard. Government agents, working with
Luke Cage, add Crossbones to the team knowing that he cannot be reformed, hoping that his extreme methods will alienate the other Thunderbolt members and push them towards rehabilitation. During the team's first mission, Crossbones was exposed to corrupted
Terrigen Mists; during the events of
Shadowland, Crossbones manifested the ability to fire a powerful, piercing beam of energy from his face, theorizing that this ability originates from his exposure to the Terrigen Mist. He uses this ability to murder a police officer. Fearing that the Thunderbolts are close to being disbanded following Cage's decision to leave, Crossbones attempted to escape alongside
Ghost and
Juggernaut. During the attempt, Crossbones used his new ability to fight the unsuspecting Steve Rogers. Crossbones was defeated and discharged from the Thunderbolts, after Ghost revealed his murder of the police officer. Crossbones is shown incarcerated in a padded cell wearing a straitjacket, apparently no longer able to use his energy beam. During the "
Fear Itself" storyline, Crossbones was constantly harassed while he was behind bars, because he was both a former Thunderbolt member and a Neo-Nazi. Shortly after when he was being beaten up by more thugs, Juggernaut unintentionally causes a break out at the
Raft. Man Mountain Mario (the cousin of
Man Mountain Marko) helps defend Crossbones from the thugs. While the two of them were trying to escape, Mario told Crossbones about his grandma who helps criminals leave the border. Crossbones manages to escape, killing Mario in the process. Crossbones was among the villains who were contracted by the
Assassins Guild to target
Elektra's allies. Crossbones later appears as a member of
Hydra who are planning to spread poisonous blood extracted from an
Inhuman boy named Lucas. He fights Sam Wilson as the new Captain America on
Bagalia. Just as he was about to kill Wilson, he is defeated by
Misty Knight who was undercover at that moment. He is later defeated by Wilson when he attacks a Hydra base located on Florida. During the "
Avengers: Standoff!" storyline, Crossbones was an inmate of Pleasant Hill, a gated community established by S.H.I.E.L.D. When Steve Rogers is at the Pleasant Hill Bowling Alley trying to reason with
Kobik, Crossbones attacks Rogers. Before Crossbones can kill Rogers, Kobik's powers de-age Rogers to his physical prime, which allows him to defeat Crossbones. In the aftermath of the events at Pleasant Hill, Crossbones founds a new version of Hydra with the Red Skull and Sin. During the "
Devil's Reign" storyline, Crossbones appears as a member of Mayor
Wilson Fisk's Thunderbolts. ==Powers and abilities==