- "There was an idea to bring together a group of remarkable people, so when we needed them, they could fight the battles that we never could."
- ―Nick Fury about the Avenger Initiative.[src]
The Avengers, or the Avenger Initiative, was a S.H.I.E.L.D. project to create a team of superheroes to help protect the Earth and humanity. Initiated by Nick Fury with the help of S.H.I.E.L.D. officers such as Phil Coulson and Natasha Romanoff (the Black Widow), S.H.I.E.L.D. managed to sway Tony Stark to the project, who had at that point recently begun acting as a superhero under the name of Iron Man.
In 2010, after Tony Stark defeated Ivan Vanko, S.H.I.E.L.D. concluded that Tony was volatile and was not fit to work in a team, and instead made him a consultant for the Initiative rather than an actual member. Some time later, the World Security Council ordered S.H.I.E.L.D. to ask General Thaddeus Ross to free Emil Blonksy, the Abomination, from prison, since they blamed Bruce Banner for the disaster in New York City. Agents Phil Coulson and Jasper Sitwell disagreed with the Council's judgment and sent Tony Stark to meet with General Ross, where Stark ended up annoying Ross so much that he would not release Blonsky. The same year, S.H.I.E.L.D. discovered Captain America, Steve Rogers, frozen in ice, for seventy years since crashing the Valkyrie into the arctic cap. Captain America, at first disoriented by the new environment he found himself in, joined Nick Fury's team.
After Loki discovered the Tesseract was located in a S.H.I.E.L.D. facility on Earth, he transported himself to the facility and dispatched most guards, while enchanting several agents to his cause, including Clint Barton (Hawkeye) and Erik Selvig. With Loki having taken the Tesseract and leaving a wounded Nick Fury behind in the facility, Fury decided to start the initiation of the Avenger Initiative and ordered Coulson to round up its candidates. Steve Rogers and Bruce Banner were brought to S.H.I.E.L.D.'s Helicarrier, which soon traced Loki's location in Stuttgart, Germany. Captain America faced Loki and was joined by Iron Man, who managed to subdue Loki and Loki peacefully surrendered. While bringing Loki back to the Helicarrier in a helicopter, the vehicle was infiltrated by Thor, Loki's adoptive brother who had been under the assumption that Loki was dead. Taking Loki to the ground to question him and take him back to Asgard, Thor was attacked by Iron Man and later Captain America before they all decided their fighting was pointless. Loki was imprisoned in the Helicarrier and Thor joined forces with S.H.I.E.L.D.
After a while, the Helicarrier was attacked by Clint Barton leading a team of soldiers under Loki's spell, who blew up one of the Helicarrier's four engines during their attack. The explosion caused the team to get separated, with Iron Man and Captain America going to fix the engine and Black Widow and Banner getting stuck under debris. Unable to control himself, Bruce transformed into the Hulk and started attacking Black Widow while leaving a trail of destruction behind him. Captain America and Iron Man eventually managed to fix the engine, while Thor rescued Black Widow from the Hulk. A S.H.I.E.L.D. jet later started firing at the Hulk to get his attention, but the Hulk instead jumped at the plane and tore it apart, causing it to explode and making him fall to the ground. Simultaneously Loki managed to escape and Thor was locked up in the process. Agent Coulson tried to stop Loki but was fatally stabbed in the back by Loki, and Loki made his former cell that now contained his brother fall to the ground; however, Thor managed to use Mjølnir to make his escape before the cell made impact with the ground.
With the Helicarrier severely damaged and the team separated from each other, Loki had Erik Selvig install a device atop Stark Tower that would protect the Tesseract while it opened a portal to the Chitauri homeworld, and a Chitauri army under the command of Loki was unleashed upon New York City. Iron Man, Captain America, Thor, Black Widow and Hawkeye (who had been captured and regained his consciousness) relocated to New York City and faced the Chitauri. Later joined by the Hulk, the Avengers stood their own against the huge numbers of the Chitauri army until news came in that the World Security Council had launched a nuclear rocket towards New York City to deal with the Chitauri threat. Black Widow had made her way to the Tesseract and managed to dismantle it with the help of Erik Selvig, while Iron Man intercepted the rocket and quickly took it through the closing portal and sent it towards the Chitauri army, before Iron Man fell back through the portal and down to the Earth. The Hulk rescued Iron Man in mid-air and the Avengers rejoiced at their victory. Thor took Loki back to Asgard and the other Avengers each went their separate ways.