How 'Civil War' Happened in Marvel Comics: Revisiting the Saga 20 Years Later

Twenty years after Mark Millar and Steve McNiven's Civil War split the Marvel Universe in two, revisit every pivotal moment — from the Stamford Incident and the Superhuman Registration Act to Spider-Man's unmasking, the death of Bill Foster, and the assassination of Captain America. Plus, the complete reading order for the entire crossover event.

How 'Civil War' Happened in Marvel Comics: Revisiting the Saga 20 Years Later

Twenty years ago, the Marvel Universe went to war with itself. In Mark Millar and Steve McNiven's now-iconic Civil War (2006), Earth's Mightiest Heroes were forced to register their secret identities with the government — or risk becoming outlaws under the Superhuman Registration Act. Iron Man spearheaded the new law, Captain America led the resistance, and the conflict touched every corner of the Marvel Universe.

To mark the 20th anniversary, let's rewind the tapes. From the deaths of major heroes to dramatic betrayals, here are the moments that defined Civil War — a saga whose effects still ripple through Marvel Comics today.

Cover art from Civil War (2006) #1 by Mark Millar and Steve McNiven
Civil War (2006) #1 by Mark Millar and Steve McNiven — the issue that ignited the conflict.

Civil War: The Essentials

The Stamford Incident

Civil War began when a group of teenage heroes called the New Warriors accidentally destroyed a city in Connecticut while filming an episode of their reality show. Speedball, Night Thrasher, Microbe, and Namorita approached a home in Stamford where several villains were hiding. As they descended on the villains, Nitro used his explosive powers to unleash a massive blast that leveled most of Stamford in Civil War (2006) #1.

Nitro's blast seemingly killed the New Warriors, the villains Coldheart, Speedfreak, and Cobalt Man, and up to 600 civilians. The Stamford Incident turned much of the public against superheroes and expedited the passage of the Superhuman Registration Act. Speedball and Night Thrasher actually survived, but the damage was done — and Wolverine and Namor hunted Nitro down to bring him to justice.

Iron Man defending the Superhuman Registration Act in Civil War (2006) #1
The aftermath of Stamford as depicted in Civil War (2006) #1.

The Superhuman Registration Act Passes

After Stamford, the United States government responded by passing the Superhuman Registration Act. The law required every superhuman in the country to register their secret identity with the government. Iron Man became one of the act's first and most ardent defenders — even before Stamford, Tony Stark had lobbied influential heroes, believing registration was inevitable and that supporters could shape what it would look like.

While Doctor Strange and Namor opposed the idea, Mister Fantastic backed Stark's plan. Once the act became law, heroes including Black Widow, Ms. Marvel (Carol Danvers), Wonder Man, She-Hulk, and the Sentry rallied behind Iron Man. Several villains also signed on, joining the government-sanctioned Thunderbolts to help enforce registration.

Cover of Civil War (2006) #2 featuring Captain America's resistance
Civil War (2006) #2 — the issue that introduced the Secret Avengers.

Captain America Goes Rogue

As soon as he learned about the Superhuman Registration Act, Captain America emerged as the law's most steadfast opponent. S.H.I.E.L.D. Commander Maria Hill tried to bring Steve Rogers on board, but Cap refused to support a law that restricted heroes' freedoms or endangered their families. As S.H.I.E.L.D. agents tried to capture him, he escaped the Helicarrier — and instantly became an outlaw, as well as the de-facto leader of the Anti-Registration movement.

Numerous heroes joined him, forming the Secret Avengers in Civil War (2006) #2. The group included Falcon, Cable, Luke Cage, Hercules, and the Young Avengers, hiding in bunkers and using new identities to stay ahead of S.H.I.E.L.D. As the government arrested more unregistered heroes, Human Torch, Invisible Woman, and the Punisher also joined the underground resistance.

Captain America leading the resistance in Civil War (2006) #2
Cap's defiance turned him into an outlaw — and a symbol of the resistance.

Spider-Man Unmasks

During their time on the New Avengers, Iron Man and Spider-Man became close allies. Tony designed Peter's Iron Spider armor, and the wall-crawler moved into Avengers Tower with Mary Jane and Aunt May. Iron Man urged Spider-Man to support registration. Peter had his doubts, but ultimately took Stark's side, unmasking himself during a press conference on live TV to encourage public support.

Peter Parker's closest friends and family supported the unmasking, but J. Jonah Jameson and others felt betrayed. Once the conflict ended, Spider-Man's identity remained public knowledge — forcing Peter to turn to the occult to restore his secret in the controversial story arc that followed.

Spider-Man unmasking on live television in Civil War (2006) #2
Spider-Man's televised unmasking remains one of the most consequential moments of the entire Marvel Comics era.

Prison 42

Before Civil War, a paranoid Mister Fantastic built a superhuman prison called the Vault in the Negative Zone. Although designed to hold the Fantastic Four's villains, Reed Richards found a new use for it once he became a leading figure of the Pro-Registration cause. He and Iron Man transformed the Vault into Prison 42, a massive complex built to hold heroes and villains who refused to comply with the law.

During the conflict, Prison 42 held heroes like Wiccan, Prowler (Hobie Brown), Cloak, Dagger, and Danny Rand posing as Daredevil in Civil War (2006) #5. As Tony Stark tried to talk Iron Fist into joining the Pro-Registration effort, Rand handed him a symbolic silver coin and called him a traitor.

Prison 42 in the Negative Zone in Civil War (2006) #5
Prison 42 in the Negative Zone became the most controversial symbol of the Pro-Registration regime.

Project Lightning and the Death of Bill Foster

When the Avengers split into opposing sides, one of the team's oldest members — Thor — was notably absent. The Asgardian god of Thunder had died during a recent crisis. But Iron Man and his allies had godlike contingencies through Project Lightning: using a strand of Thor's hair and sophisticated cybernetic technology, they created a clone of Thor.

During a fight between the two factions, the Thor clone killed Goliath (Bill Foster), a size-changing hero, by shooting a beam of electricity through his chest in Civil War (2006) #4. Foster's death shocked both sides and triggered defections from each camp. Hercules later used the clone's fake Mjolnir to destroy the cybernetic Thor in the final showdown. The real Thor returned to life shortly after the conflict ended.

The Thor clone killing Goliath Bill Foster in Civil War (2006) #4
Goliath's death in Civil War (2006) #4 became the moral turning point of the war.

Spider-Man Switches Sides

Spider-Man may have entered Civil War as one of Iron Man's supporters, but he defected to Captain America's Secret Avengers in Civil War (2006) #5. When Peter learned that Iron Man had been tracking his suit and imprisoning heroes in the Negative Zone, he confronted his mentor — who sent 14 registered villains after him. They nearly killed him, but the Punisher found Spider-Man and rushed him to Captain America's base.

While the Secret Avengers kicked the Punisher out for killing two surrendering villains, Spider-Man joined the team. He announced his change of heart by exposing Prison 42 in a news conference and joined the final battle against Iron Man. Following the conflict, Spider-Man remained an outlaw vigilante — and one of Kingpin's snipers shot Aunt May in retaliation for the public unmasking.

Spider-Man defecting to Captain America's Secret Avengers in Civil War (2006) #5
Spider-Man's defection in Civil War (2006) #5 was the war's biggest swing.

The Young Avengers Meet the Runaways

While the New Warriors accidentally kicked off the war, the conflict also brought together two other groups of teenage heroes: the Young Avengers and the Runaways. After witnessing a battle between the Runaways and S.H.I.E.L.D. on TV, the Young Avengers traveled to Los Angeles to investigate the group's connection to their teammate Vision, in Civil War: Young Avengers/Runaways (2006) #1 by Zeb Wells and Stefano Caselli.

Following a brief fight between the teams, a mind-controlled Marvel Boy (Noh-Varr) captured unregistered members of both groups. The teen heroes rescued their teammates and freed Marvel Boy from his conditioning, with the Young Avengers returning to the Secret Avengers and the Runaways going underground.

Cover of Civil War: Young Avengers/Runaways (2006) #1 by Zeb Wells and Stefano Caselli
Two groups of teenage heroes collide in Civil War: Young Avengers/Runaways (2006) #1.

Captain America Surrenders

The final battle started in the Negative Zone and spilled out onto the streets of New York in Civil War (2006) #7. Captain America and his Secret Avengers maintained the upper hand, but several civilians stopped him from landing a final blow on Iron Man. Cap stood down and ordered his allies to stop fighting when he realized the destruction they'd left in their wake. After unmasking, Steve Rogers surrendered to the police.

In the aftermath, some of Captain America's unregistered allies continued to operate as the New Avengers, but many more heroes and villains joined the Initiative — a U.S. government policy that put a registered super-team in every state.

Captain America surrendering at the end of Civil War (2006) #7
Steve Rogers surrenders in Civil War (2006) #7 — a stunning end to the conflict.

The Death of Captain America

Captain America became the final casualty of Civil War when he was fatally shot in Captain America (2004) #25 by Ed Brubaker and Steve Epting. As he walked into a courthouse for his trial, the Red Skull hired Crossbones to shoot him. Under the influence of the mind-twisting Doctor Faustus, Sharon Carter — Cap's longtime partner — also shot him in the stomach three times to seal the deal.

When Cap died, his closest allies pursued the Red Skull. Iron Man received a note asking him to look after the recently deprogrammed Bucky Barnes, so Tony Stark passed the shield and mantle to the former Winter Soldier. Steve Rogers was eventually revived, his consciousness rescued from the timestream, but the assassination ended the Civil War era on a famously dark note.

Captain America (2004) #25 by Ed Brubaker and Steve Epting depicting Steve Rogers' assassination
Captain America (2004) #25 by Ed Brubaker and Steve Epting closed the Civil War era.
"The Avengers may have faced dozens of crises since Civil War, but the effects of this saga still reverberate around the Marvel Universe today."

Civil War: The Complete Reading List

Want to revisit the entire saga in publication order? Here's the full crossover lineup, all available on the Marvel Unlimited app and web.

Civil War: The Complete Event reading list cover image

Civil War: The Complete Event

Cover of Amazing Spider-Man (1999) #529

Amazing Spider-Man (1999) #529

Cover of Amazing Spider-Man (1999) #530

Amazing Spider-Man (1999) #530

Cover of Amazing Spider-Man (1999) #531

Amazing Spider-Man (1999) #531

Cover of Fantastic Four (1998) #536

Fantastic Four (1998) #536

Cover of Fantastic Four (1998) #537

Fantastic Four (1998) #537

Cover of New Avengers Illuminati One-Shot (2006) #1

New Avengers: Illuminati One-Shot (2006) #1

Cover of Civil War (2006) #1

Civil War (2006) #1

Cover of She-Hulk (2005) #8

She-Hulk (2005) #8

Cover of Wolverine (2003) #42

Wolverine (2003) #42

Cover of Amazing Spider-Man (1999) #532

Amazing Spider-Man (1999) #532

Cover of Civil War: Front Line (2006) #1

Civil War: Front Line (2006) #1

Cover of Civil War (2006) #2

Civil War (2006) #2

Cover of Thunderbolts (2006) #103

Thunderbolts (2006) #103

Cover of Civil War: Front Line (2006) #2

Civil War: Front Line (2006) #2

Cover of X-Factor (2005) #8

X-Factor (2005) #8

Cover of New Avengers (2004) #21

New Avengers (2004) #21

Cover of Wolverine (2003) #43

Wolverine (2003) #43

Cover of Amazing Spider-Man (1999) #533

Amazing Spider-Man (1999) #533

Cover of Fantastic Four (1998) #538

Fantastic Four (1998) #538

Cover of Civil War: Front Line (2006) #3

Civil War: Front Line (2006) #3

Cover of Thunderbolts (2006) #104

Thunderbolts (2006) #104

Cover of Civil War: X-Men (2006) #1

Civil War: X-Men (2006) #1

Cover of Civil War (2006) #3

Civil War (2006) #3

Cover of Cable & Deadpool (2004) #30

Cable & Deadpool (2004) #30

Cover of Civil War: Young Avengers & Runaways (2006) #1

Civil War: Young Avengers & Runaways (2006) #1

Cover of Civil War: Front Line (2006) #4

Civil War: Front Line (2006) #4

Cover of X-Factor (2005) #9

X-Factor (2005) #9

Cover of New Avengers (2004) #22

New Avengers (2004) #22

Cover of Wolverine (2003) #44

Wolverine (2003) #44

Cover of Amazing Spider-Man (1999) #534

Amazing Spider-Man (1999) #534

What Civil War Means 20 Years Later

Two decades on, Civil War is still the template Marvel reaches for when it wants to ask the hardest question superhero fiction can pose: who watches the watchmen, and at what cost? The 2006 saga's DNA shows up everywhere — from the MCU's Captain America: Civil War to ongoing comics that keep relitigating registration, surveillance, and accountability. The Avengers may have faced dozens of crises since, but the effects of Mark Millar and Steve McNiven's epic still reverberate across the Marvel Universe.

Whether you experienced Civil War as it unfolded in 2006 or you're discovering it for the first time on Marvel Unlimited, the saga is a reminder that the most dangerous fights in comics aren't with cosmic gods or alien armies — they're between heroes who used to be friends.