The Avengers (also known as Earth's Mightiest Heroes) are a team of superheroes that are based in New York City. Led by Iron Man as team-leader and Captain America as field-leader, including; such members as Thor, Hawkeye, Black Widow, Falcon and Hulk, they are the Earth's foremost defense against super-powered threats. The team was originally headquartered in the Avengers Mansion, but after it's destruction, the team has moved into Stark Tower, now called Avengers Tower.
In the early days since their formation, the Avengers encountered and fought Molecule Man, a short but difficult battle they won. At some point in time, the Avengers split up and went their separate ways; the reason being unknown. It's unknown who else was in the Avengers prior to the series; because when Tony took over as leader he tells the others that the Avengers were coming back, handpicked by him. Meaning that there were more members then the seven current members.
After Captain America's supposed "death" at the hands of Red Skull, Iron Man activated the Avengers Protocol, effectively reassembling the disbanded team to avenge. Iron Man specifically called in Thor, The Hulk, Black Widow, Hawkeye, and Falcon to raid Skull's new base in Antarctica and avenge Cap. When it was discovered that Cap was alive, the team decided to stay together since the Skull stole Iron Man's Mark 49 Armor and started his own Cabal.
Splintering of the team
After Iron Man repeatedly led the Avengers into battle against Ultron without telling the team, Captain America left. The next battle with Ultron that resulted in the destruction all Stark Tech (save for the armor he was currently wearing) resulted in Black Widow, Falcon, and Hulk leaving the team as well. Captain America, Black Widow, Falcon and Hulk formed the Secret Avengers team that is employed and funded by S.H.I.E.L.D..
Finding of the Infinity Stones
The Power Stone, the Time Stone, the Mind Stone, the Reality Stone and the Space Stone were searched by the mighty Titan, Thanos.
Reformation of the team and the joining of Ant-Man
After the events of the Ultron Outbreak, Captain America, Black Widow, Hulk, and Falcon rejoin the Avengers after resigning from S.H.I.E.L.D. Both Iron Man and Captain America says Avengers Reassemble and Ant-Man starts to walk away. Iron Man then says 'Avengers means you too Ant-Man'. Both Ant-Man and Hawkeye are surprised in which Iron Man says 'relax Hawkeye, our differences makes us stronger, remember?' Ant-Man nudges Hawkeye and Iron Man says 'Avengers Assemble.'
After discovering that the Avengers are more than just it's membership they began to plan for expanding the membership.
The Avengers haven't been working together on a regular basis after beating Red Skull, Thanos, and Ultron. During this time Ant-Man went solo again and they cancelled their expansion plans. Also Tony begins to use F.R.I.D.A.Y. to replace J.A.R.V.I.S. As a result of their not working together their ability to work as a team has diminished considerably which nearly made them loose to A.I.M.'s trio of upgraded Super-Adaptoids.
One subplot details Baron Zemo, son of Captain America's old nemesis Baron Heinrich Zemo, finding a working vial of the Super-Solider serum and uses it on himself to gain the youth and strength to face the Avengers defeat and destroy them in order to avenge his father's death. Then he recruits the Masters of Evil (which consists of Beetle, Goliath, Screaming Mimi, Fixer, and Moonstone) and steals a device from Stark Industries called the Inversion Stabilizer that allows them to masquerade as the Thunderbolts (with Zemo going under the alias Citizen V while each of the Masters of Evil above become MACH-IV, Atlas, Songbird, Techno, and Meteorite respectively) in a plot to undermine the Avengers. But after being saved from death by Hawkeye during the robbery and seeing what it's like be a hero, Songbird convinces the rest of the team to turn on Zemo. Together, the Avengers and Thunderbolts expose Zemo and defeat him.
The Avengers must also contend with Kang the Conqueror when he arrives in the present following his brief fight with Iron Man in his time and discovering that some A.I.M. Agents have been using his technology to upgrade some supervillain gear like they did to Whiplash and Spymaster. When most of the Avengers follows Kang the Conqueror back to his time, the Avengers team up with an elderly Thor, a future Black Widow named Layla, and a group of rebels in order to fight the forces of Kang the Conqueror.
When the President signs the New Powers Act, the Avengers are given Truman Marsh as their government liaison where he even replaces Hulk with Red Hulk until the incident where Leader gamma-enhances him enough for Hulk to return.
As the Avengers disassociate themselves with Truman Marsh during the Inhuman Registration Act that involves Registration Disks placed on them, Truman Marsh assembles Red Hulk, Black Panther, Songbird, Ant-Man, Captain Marvel, Ms. Marvel, and Vision as the Mighty Avengers. The superhero fight lasts when the Inhumans Karnak, Gorgon, Inferno, Haechi, Flint, Iso, and Ms. Marvel gets mind-controlled through the disks by Ultron posing as Truman Marsh as he starts the Ultron Revolution. When the Inhumans are freed from the mind-control, Ultron plans to collect radiation to "sanitize" Earth of all human life. With help from Doctor Strange at the time when Ultron takes control of Iron Man's body, the Avengers were able to place Iron Man in another dimension until they can find a way to drive Ultron out. Setting up in an abandoned S.H.I.E.L.D. facility, the Avengers operate from there as Falcon sets up an inter-dimensional frequency for Tony Stark to speak to them through.
The Avengers' plans to bring Tony Stark back from another dimension experience a major setback when a new version of the Cabal (consisting of Leader, Arnim Zola, Enchantress, Executioner, and Kang the Conqueror) is formed, with Leader planning to use his Static expander device on the captive Avengers. Black Panther forms the New Avengers to rescue them which consists of Ant-Man, Captain Marvel, Ms. Marvel, Vision, and Wasp. Even though Leader is defeated, Enchantress and Arnim Zola reveal that Leader is not the true leader of the Cabal as they activate the fail-safe that activates the Static Expander to scatter the captive Avengers across time and space. Before disappearing, Captain America instructs Black Panther's group to continue in their place until they can be found and brought home.
The New Avengers work to find a way to bring the Avengers home while combating various threats in their place. After Jane Foster locates the Avengers, she provides the New Avengers special tether bracelets to send them to rescue the Avengers from each location where a member of the Cabal is overseeing. Vision and Wasp find that Falcon had spent a few years time in a dystopian future New York City to help Kang stop a black hole and they prevent Kang from using it to further his conquest, Ant-Man helps Captain America, Hawkeye and Black Widow escape from Dimension Z and free it from Arnim Zola's control, Black Panther and Hulk manage to survive a hunt by Executioner in the Asgardian wilderness, and Captain Marvel and Ms. Marvel help free Thor from the Enchantress' control on her icy asteroid kingdom in deep space. Afterwards, both teams return to Earth to find that the Cabal's true leader Loki has taken over Earth with the Casket of Ancient Winters and the use of a swarm of dragons, an army of Frost Trolls and the World Breaker ships that will destroy Earth upon his signal. Both teams of Avengers defeat Loki and imprison him in their base as he vows that his plans aren't over.
As it turns out, Loki had told a being called the Beyonder about Earth's existence who to Loki's dismay uses the Bifrost Bridge to take parts of Earth, Asgard, and other realities, including the one where Tony Stark was stranded, in order to form Battleworld for his "experiment". With Iron Man back, the Avengers must form an unlikely alliance with Loki to rebuild the Bifrost Bridge and get everyone back to Earth. To build a new Bifrost Bridge, the Avengers needed Loki to design the Bifrost, Heimdall's sword, Vibranium, Doctor Strange to use his magic to open the Bifrost as Sorcerer Supreme, Bruce Banner's knowledge of radiations and the key of Beyonder's magical tech to connect the Bifrost with every part of the Battleworld.
When they finished it, the Avengers secretly placed it in Olimpo, where it could affect all the Battleworld at once and bring everything to normal. Constantly hunted by the Beyonder and Ares with the Ghost Riders, Earth's Mightiest Heroes split on teams to handle the Beyonder. During the prepare to open the Bifrost, Doctor Strange is hurt in battle and passes the Eye of Agamotto to Loki to conclude himself the spell. At the final moment, Beyonder traps all the Avengers including Jane Foster that began to fall in quicksand. Thor seeing Jane being killed frees one of his arms and launches Mjolnir to Beyonder turning himself to Jane Foster freeing her and transforming in the New Goddess of Thunder defeating the Beyonder alone once and for all. With the Beyonder defeated, the Avengers have the victory but they have no idea that a bigger threat is yet to come.
Final Battle: Avengers vs All-Mighty Loki
After winning the Secret Wars, the Avengers are brought to Asgard in the Bifrost Bridge and they celebrate until Doctor Strange asks Loki to give him back the Eye of Agamotto but Loki refuses and he reveals that he has been using the Avengers to get at this point of trust. Loki as Sorcerer Supreme banishes the Avengers back to Earth with the exception of Thor. They plan how to get to get to Asgard to fight Loki and rescue Thor since Loki closed all magical portals to get into Asgard even with Thor's hammer, they could not go, even if Jane Foster knew how to use the hammer. Disappointed with herself, Jane Foster closes herself in the lab; until Wasp and Ms. Marvel will comfort her by recounting all her adventures giving Jane Foster the idea of using the dimensional teleportation she used to find the marooned Avengers. At that time, on Asgard, Loki fights against Odin reclaiming the title of All-Father from Odin imprisoning him in a cell.
As Sorcerer Supreme and All-Father, Loki became unstoppable joking with his brother threatening him of unleashing All-Dark Magic from the Casket of Eternal Darkness and with his hammer revealing him to be as the All-Father capable of lifting the hammer until Jane Foster and the Avengers arrive ordering the hammer to her. Later on, Loki unleashes an army of Frost-Mindless Ones to attack Earth splintering the team again knowing that their weakness is that they aren't going to be able to protect everybody. To fight Loki it only rests Thor, Jane Foster and Doctor Strange. In an intense battle both the Avengers and the Trio are unable to stop their enemies forever; until Loki went crazy enough launching the dark magic to Yggdrasill, the Tree of Life, menacing all life in existence.
Then Thor seeing his brother's insanity to win, he asks him to use the Eye of Agamotto to show him the Trur, that even being All-Mighty he wouldn't survive to such destruction. In the end, Loki rejects the Eye of Agamotto back to Strange citing that the amulet lies. Together Doctor Strange and "Thors" destroy the Darkness in the tree. When Loki gets mad against the Avengers the ashes of black magic join his body destroying it. With that the Avengers finally have peace.
- Iron Man (founder and leader)
- Captain America (second-in-command and field-leader; former leader)
- Captain Marvel (former second-in-command)
- Black Panther (former leader)
- Black Widow
- Wasp (Hope Pym)
- Ms. Marvel
Avengers academy students
- Black Bolt
- Doctor Strange
- Moon Knight
- Winter Soldier
- War Machine
- White Wolf
The Mighty Avengers are a team assembled by Truman Marsh after the Avengers refused to comply with the Inhuman Registration.
- Captain Marvel
- Black Panther
- Red Hulk (was on the main team; replaced Hulk because of Truman Marsh, joined in U-Foes; left team in World War Hulk for medical reasons after absorbing vast Gamma radiation because of the Leader)
- Ms. Marvel
- Songbird (defected to the main team)
The New Avengers are a team assembled by Black Panther after the Main Avengers mysteriously disappeared.
- Black Panther (founder and leader)
- Captain Marvel (second-in-command and field-leader)
- Wasp (Hope Pym)
- Ms. Marvel
- Shadow Council
- Doctor Doom
- Squadron Supreme
- Arnim Zola
- Kang the Conqueror
- Black Order
- Tiger Shark's Elite
- Midgard Serpent
- Justin Hammer
- Rock Trolls
- Frost Giants
- Heinrich Zemo
- Grim Reaper
- Crimson Widow
- Typhoid Mary
- Blood Brothers
- Circus of Crime
- Frightful Four
- Fin Fang Foom
- Winter Guard
- Scientist Supreme
- Growing Man
- Igor Drenkov
- Cobalt Man
- Doctor Faustus
- Before it was destroyed, Avengers Mansion had a memorial hall with eight statues of deceased Avengers. 
- In the comics, the original members of the team were Iron Man, Thor, Hulk, Ant-Man (Hank Pym), and Wasp (Janet Van Dyne). In the show, which is heavily based on the Marvel Cinematic Universe, the team's original lineup consisted of Iron Man, Captain America, Thor, Hulk, Black Widow and Hawkeye.