Avengers

"What have I to fear?" "The Avengers. It's what we call ourselves, sort of like a team. "Earth's Mightiest Heroes" type thing."

- Loki and Tony Stark

The Avengers are a team of super-heroes assembled by Nick Fury and S.H.I.E.L.D through the Avengers Initiative.

History
The Avengers are the result of S.H.I.E.L.D. Director Nick Fury. Nick Fury realized that a group of extraordinary individuals would be needed to the battle the growing forces that conventional military forces would not be able to handle, much less defeat. The founding memebers are Captain America, the world's first "superhero", the Invincible Armored Iron Man, the Asgardian God of Thunder, Thor, Bruce Banner aka the Hulk and two of S.H.I.E.L.D.'s most skilled operatives, Clint Barton, aka Hawkeye and Natasha Romanoff aka the Black WIdow.

Iron Man
After revealing to the world that he is Iron Man, Tony Stark return to find Fury waiting on him. He wanted to talk to him about the Avengers Intiative. Stark declined but Fury still kept eyes on him in the meantime.

Iron Man 2
Six months after revealing to the world that he was Iron Man, he has helped stablized peace between the East and the West. However, he came to find out the the very thing that is keeping him alive, the Palludum Arc Reactor, was slowly killing him. Starting to do questionable things such selling some of his things and giving Pepper control of Stark Industries and after run-ins with Vanko and Rhodes at his house on his birthday while in a druken stupdor, resulted in Fury interventing once again. First, before the run-ins with Vanko and Rhodes, he placed Romanoff in as Natalie Rushman to keep eyes on him. Secondly, he came to meet with to discuss his condition and help him put back on the path to save himself and back to work. After finding the new element and defeating Vanko, however, Romanoff wrote a report on Stark and stated while the armor would benefit the Avengers Intiative, Stark himself was deemed unsuitable and was given a position as consultant which he accepted on the condition that he and Rhodes was given medals personally by Sterns.

The Incredible Hulk
After the Battle of Harlem, Ross was in a bar, drinking his failure away when Stark appeared into the bar, reminding him why the Super Soldier Project was "put on ice." Ross reminded him what "nice sutis he wear." After that, Ross proposed that they are putting a "team" together.

Thor
After Thor was exiled to Earth and landed in New Mexico, he tried to recover Mjolnir after discovering it had made its way to Earth too. Coulson made note of Thor's strength, albeit human, and his combat skills, making his men "some of the most highly trained professionals in the world look like minimum wage mall cops." Then when the Destroyer can to Earth to kill Thor and near-death, Thor regained his power and defeat the Destroyer. After that, Coulson approached him but Thor vowed he would be an ally to Earth if they return Jane's research which Coulson agreed. However, before Coulson had a chance to debrief him, Thor flew to the landing site to return back to Asgard to stop Loki.

Captain America: The First Avenger
Steve Rogers woke up in an 1940s style hospital to find something wrong. When he realized the game that was playing on the radio was a game he had already seen, he had escaped onto the streets of 2010s New York. There, he was meeted by Nick Fury who told him the entire incident was to break the news to him slowly that he had been missing for 70 years. Later, in a gym, while Rogers was working out his frustation on a punching bag, Fury approached him with a mission to save the world once again.

The Avengers
At first, when it looks to be no traction with it, the Avengers Intiative was shut down. Instead, focus was put on Phase 2, reverse-enginerering alien technology to create weapons for defense of the planet and looking at the Tessaract as a source of that. However, upon Loki's arrival from parts unknown through the Tessaract and attacking several S.H.I.E.L.D. agents and taking over Agent Barton and Erik Selving with his staff and taking hold of the Tessaract. After this, Fury re-activiates the Avengers Intiative. He has Coulson called for Romanoff for bringing in the others. He has her go to India to bring in Bruce Banner who can track the cube due to the fact that it is emitting low levels of gamma radiation and him being the expert. Meanwhile, Fury goes to Rogers himself to him his first orders since being awakening. Coulson goes to Stark Tower later that evening to bring files to Stark on his other potential teammates and Loki and the Tessaract which he looks at due to Pepper's influence and her friendship with Coulson. The team initially have difficulty and refusal to obey each other; for example, Tony Stark is reluctant to working under the command of Captain America, Thor demands that Loki is his responsibility and the team is uncomfortable with the presence of Bruce Banner. When Loki kills Coulson, attempts to destroy the team and promote his godlike supremecy to Earth in a public way, the Avengers put their differences aside, learning to trust one another and depart from S.H.I.E.L.D.'s command and rally in defense of New York as it is invaded by the extraterrestrials known as the Chitauri. Captain America takes command of the team and they each work to supress the invasion force. The Hulk beats Loki into submission and Iron Man sends a nuclear weapon fired by the World Security Council into the portal through which the aliens enter Earth and their fleet is destroyed, breaking the neural connection with their ground troops and instantly killing them. The team take Loki as their prisoner and Thor takes both Loki and the Tesseract back to Asgard. The team disbands but agrees to reassemble when another global threat requires their combined efforts.