For the team appearing in Fearless Defenders please use the appropriate page: Valkyrior.
The Defenders was a team of heroes first brought together by circumstance. The initial membership included Dr. Strange, the Hulk, Namor the Submariner, and the Silver Surfer. It all started when Dr. Strange gathered the Hulk, Namor, and the Silver Surfer to stop Yandroth's evil machine.
A proto-Defenders non-group called the Titans Three first appeared in Sub-Mariner #35, written by Roy Thomas and drawn by Sal Buscema. It consisted of Namor, The Hulk, and The Silver Surfer who banded together to destroy an experimental weather changing device. Roy Thomas also wrote the first official appearance of the Defenders, with Ross Andru doing the pencils and Bill Everett doing the inks, for Marvel Feature #1 in 1971. This team consisted of Namor, The Hulk, The Silver Surfer and Doctor Strange. Throughout the life of the Defenders, the team line-up has been quite fluid with members. There were always a number of core members who had extended stays such as Nighthawk, Hellcat, Luke Cage, Red Guardian, or Valkyrie, and others who only joined for one or two adventures at a time.
Major Story Arcs
Avengers Defenders War
Loki and Dormammu trick the Defenders into recovering the Evil Eye so Dormammu can finally unleash his influence in the whole world. Loki, however, changes his plans by fearing that Dormammu may conquer Asgard as well, and without Dormammu's consent he tricks the Avengers in fighting against the Defenders in an attempt to stop the Defenders from recovering the Evil Eye.
One of the Defenders' major challenge was to stop two world threats that were happening at the time: A group of outcast mad scientists known as the Headmen schemed to dominate the world by influencing the political and economic system,while space deity Nebulon, a villain whom the Defenders has fought previously, came back to Earth to bring peace to mankind by introducing them a pop pyschological movement that in reality brainwashed their victims, removing their free will and individuality.
Day of the Defenders
Aspiring filmmaker, Dollar Bill caused the majority of the confusion about the non-team called the Defenders. Unbeknownst to Nighthawk and the other Defenders, Bill made a documentary of the Defenders adventures and released it to public television. In it he declared that the Defenders were a non-team with no charter and no rules, in fact, anyone with powers who declared themselves a Defenders was automatically a member. He also revealed the location of the Defender's headquarters are the Richmond Riding Academy. Nighthawk was furious but Valkyrie assured him every thing would just blow over.
The next morning the yard was filled with new Defenders. New Defenders who came to declare themselves included Jack of Hearts, Damion Hellstorm, Polaris, Stingray, Black Goliath, Iron Fist, Captain Marvel I, Ms. Marvel I, Hercules, Nova, Marvel Boy, Falcon, Prowler, Torpedo, Captain Ultra, Paladin, White Tiger I, Havok and Tagak the Leopard Man.
This also lead to a series of criminals pretending to be Defenders while committing crimes in New York City. The villains were organized by the Zodiac's Libra and Sagittarius and included Porcupine, Whirlwind, Beetle, Blob, Plantman, Batroc, Electro, Looter, Shocker, Boomerang, Melter, Frog-Man, Toad and Joe the Gorilla. The villains were defeated by Hellcat who subdued half the the heroes and villains with an uncontrolled mindblast and the other half were defeated by a raging Valkyrie. None of the new Defenders continued as actual Defenders. (reference: Defenders 62-65) Six-Fingered Hand. The Defenders with countless guest stars battle the six-fingered Demons that lead trail straight to the Hell-Lords themselves. (During issues #94-#100)
A formally organized team of mostly new members, except for Beast, Gargoyle, and Valkyrie. This team ended after a climactic battle against the Dragon of the Moon.
Defenders (2001) & The Order
Kurt Busiek and Erik Larsen's take on the team, featured many of the regular Defenders from the first series. They come together again to fight Yandroth and become cursed. In The Order mini-series, the original Defenders served as the antagonists, who decide to take over the world for its own good.
A more tongue and cheek take on the Defenders by Keith Giffen, J.M. DeMatteis and Kevin Maguire, that featured the original members taking on Dormamuu, yet again.
New Jersey Defenders
Tony Stark, the head of SHIELD, recruited Nighthawk to be the leader of the New Jersey branch Initiative, calling them the Defenders. The other members of his team included Colossus, She-Hulk and the Blazing Skull. A New Jersey team was required because the proximity to New York demanded more experienced heroes than those recruited fresh out of Camp Hammond. Their first mission was to battle the Sons of the Serpents, who were busy summoning the god Quetzalcoatl in Trump Plaza. The mission did not fare well and the team was disbanded on the grounds of incompetence.
Since then, however, Nighthawk has gone on to gather a team outside the Initiative consisting of himself, She-Hulk, Hellstorm, and Krang, and calling themselves the Last Defenders. This team operated for a short time before being disbanded by H.A.M.M.E.R. It also showed a possible future of Nighthawk handing his mantle over to someone else.
Fear Itself: The Deep
Namor and the Atlanteans are defeated by Nerkkod, who turns the remains of New Atlantis over to his generals, Tiger Shark, Tyrrak, and Aradnea. Namor and Loa regroup on the mainland and seek the aid of Dr. Strange, who casts a spell to summon the Defenders. Busy with other threats, the only one to respond is Lyra, genetic daughter to the Hulk. The four are attacked by demon sea creatures. The Silver Surfer comes to them, claiming to have seen seven objects falling from the sky, and offering his aid, thus filling the new team roster.
Matt Fraction and Terry Dodson's Defenders team consists of original members Dr. Strange, Namor, Silver Surfer, and new members Red She Hulk and Iron Fist. It appears there will be other members rotating in and out, as Nick Fury and Ant-Man are featured in the first arc.
In the DC Animated Universe, Doctor Fate assembled a group much like the Defenders. Bruce Timm said that was an inside joker for the fans, the team consisted of:
Doctor Fate as Doctor Strange
Amazo as Silver Surfer
Solomon Grundy as Hulk
Aquaman as Namor
Hawkgirl as Valkyrie
The Defenders first appeared in Ultimates 2 with the group consisted of only Powerman, Valkyrie, Son of Satan, Nighthawk, Ant-man, Black Night, and Hellcat. They are a new super hero group with little money, equipment, or resources to be able to do crime fighting.
The only member to have powers at the time was Ant-man a.k.a. "Hank Pym" who joins the team after getting kicked of the Ultimates and sleeps with team member Valkyrie.
After trying to foil a robbery Nighthawk was greatly injured by falling on top of the robbers who beat him up and throw him out a window where he lands on top of a car.
Soon after hank Pym leaves the Defenders due to this. They reappear in Ultimates Annual with a new member called Whiz-kid who is wheelchair bound due to polio. It is also revealed that Son of Satan is an undercover S.H.I.E.L.D agent monitoring the Defenders in case they could be a potential something to them.
After Ultimatum the team undergo a dramatic change attack the Ultimates with mysterious powers looking for Thor's hammer. It is unknown how they received their new powers and what connection they still have with a powered up Valkyrie who is now a member of the Ultimates.
The Defenders of The Realm are, presumably, a back-up "security" squad created by Lord Mar-Vell specifically for the purpose of keeping those who seek to undermine The Many-Angled Ones plans to conquer Earth-616, such as Thanos, from doing just that while The Revengers are absent from their reality.
The Defenders of The Realm first appeared shortly after Thanos collapsed from the pain of being in a Universe so completely filled up with corrupted life, leaving Gamora, Drax, Rocket Raccoon, Cosmo and Starlord to keep them occupied until Mantis could figure out a way to wake Thanos back up.
The Defenders of The Realm are composed of Doctor Strange, Namor, Nighthawk, Valkyrie, Hellcat and a new and unknown replacement for the original Hulk (Bruce Banner), who had long since mutated into a feral, mindless, uncontrollable and ever-expanding tentacled horror that ended up being "slain" by The Revengers.
Age of Ultron
After Wolverine and Sue Storm traveled back in time to assassinate Hank Pym before he could prevent Ultron, a splinter timeline was created.
In the new reality, the Avengers disbanded after a catastrophy, and thus the Defenders replaced them as the premier superhero team of Earth. The group consisted of Doctor Strange, Captain America, Wolverine, Hulk, Captain Marvel (Janet Van Dyne), Cyclops, Thing, and Star-Lord.
What If...? X-Men: Age of Apocalypse
In an alternate Age of Apocalypse reality where both Xavier and Magneto are killed by Legion, Apocalypse expanded his brutal reign around the world unchallenged.
Twenty years after his rise, a band of the world's last crimefighters, dubbed the Defenders, make a final attempt in overthrowing Apocalypse and his Horsemen.
This version is led by Nate Summers, and its members consist of Brother Voodoo, Captain America, Colossus, Wolverine, Captain Britain, Thing, Sauron, and Molecule Man.
Following Doctor Strange's sacrifice, the team learns the truth of their reality and swears not to change the past but destroy Apocalypse's regime in the present. When the team finally succeeds in killing Apocalypse, however, Nate dons Apocalypse's armor and attempts time-travel to prevent their timeline from ever happening. In a fit of rage, Captain America fires a lightning bolt using Mjolnir, which not only killed Nate but also hundreds of others across the time portal.
In Other Media
A version of the Defenders appear in the episode "Planet Doom," which takes place in an alternate timeline where the Avengers were never formed and S.H.I.E.L.D. was destroyed. The team consisted of Bullseye Barton, Snap Wilson, and Slinger, with the Punisher and Black Bride as secret members of the group.
The Defenders will appear in an Netflix exclusive mini-series set in the Marvel Cinematic Universe. Confirmed members of the team include Daredevil, Luke Cage, Jessica Jones, and Iron Fist.