Founding and Early Adventures
The Mighty Avengers were formed in the wake of the Superhero Civil War as the New York unit of the 50-State Initiative. They were selected by Tony Stark, then Director of SHIELD, from members of his Pro-Registration Superhero Unit to form "the perfect team of Avengers." Stark's aim was that, though the Initiative was meant to cover each state, the Mighty Avengers would serve the world. Though he was an active team member, Stark's obligations both as Iron Man and as Director of SHIELD meant he was already strained as it was. For this reason, he appointed longtime Avenger and former super-agent Ms. Marvel to act as field commander.
Unlike the previous rosters of the Avengers which were assembled by chance, Stark and Ms. Marvel picked the line up from the registered heroes at their disposal. Aside from Iron Man, the only other founding Avenger on the roster was wealthy fashion icon Janet van Dyne, the Wasp. Following Iron Man from the New Avengers in the post-Civil War split was the troubled powerhouse known as the Sentry. Two other former Avengers rounded out the roster, in the form of Black Widow, the former Russian spy and ex-lover of Stark's, and Wonder Man, the ex-industrialist turned superheroic actor and stuntman. Ares, the Olympian God of War turned anti-hero, completed the roster. Ares was selected because it was felt that the team needed "a Thor", and "a Wolverine". 
Their first mission, just after their formation, brought them into conflict with the Mole Man. Immediately thereafter, a nanovirus courtesy of Ultron took control of Iron Man's armor, molding it into a new "female" form for its creator. Ultron went on to seize control of Stark Industries' weather satellites. It was only with the aid of Starktech 9, a robotic version of the original Iron Man armor, that the Avengers won the day. Another early venture, on the heels of the death of Captain America, saw the team, sans Iron Man, venting their anger on Tiger Shark and a host of summoned sea-beasts.
The Mighty Avengers clashed with their sometimes rivals, Luke Cage's unregistered New Avengers.They were forced to join with this same team, along with the Fantastic Four, to stave off the Hulk and his allies, to varying degrees of success. Also, the hero they believed to be Spider-Woman, already a woman of several loyalties (a mole within both SHIELD and HYDRA for the fugitive Nick Fury, in addition to Avengers duties), left the New Avengers to join the Mighty Avengers.
Next, the New York Initiative was confronted by an invasion of the Symbiotes, the same alien race that had spawned Venom and Carnage. These alien creatures rapidly began attaching themselves to people throughout Manhattan, including Wasp, Black Widow, and Spider-Woman. After Iron Man developed an antivirus, he traced the attack's origin not to outer space, but to Latveria. The Mighty Avenger travelled to Latveria and apprehended its monarch, Doctor Doom.
After it was discovered that a Skrull had posed as Elektra, Tony Stark recognized this as a sign of some kind of Secret Invasion. Although all Skrulls had shapeshifting powers, this one had proven especially difficult to detect. Stark called in Dr. Reed Richards and Dr. Hank Pym. As Richards and Pym were examining the corpse, Pym revealed that he too was a Skrull, firing a weapon at Reed that reduced his elastic body into a puddle of goo.
Meanwhile, a Skrull ship crash-landed in the Savage Land. Both teams of Avengers responded. The ship opened, however, revealing a contingent of 15 individuals dressed in old-style costumes of existing superheroes claiming to be the genuine articles, and to have just escaped Skrull imprisonment. Spider-Woman was discovered to have been none other than Veranke, Queen of the Skrulls. Not only the Avengers were affected, but the Initiative, SHIELD, and more.
During the climactic battle with the Skrulls, the Mighty Avengers fought alongside a slew of comrades. The Skrull posing as Hank Pym had offered the Wasp a dose of the serum which Pym had used to grow to immense heights as Giant-Man and Goliath. As it turned out, however, this was a trap: the serum turned her into a living bomb. As the Wasp was about to explode, killing everyone nearby, her longtime comrade Thor was forced to kill her to save everyone around her. At the same time, he promised to avenge her. During the fighting, Norman Osborn killed Queen Veranke. 
After the battle, the blame for the Secret Invasion was placed mainly on the shoulders of Tony Stark. SHIELD was disbanded, and was replaced with the new Thunderbolts Initiative headed by Norman Osborn, the Green Goblin. Osborn was secretly a member of the Cabal. Everyone replaced by the Skrulls was found to be alive and well. With the Wasp dead and Tony fallen from grace, the original lineup of the Mighty Avengers disbanded. Ms. Marvel joined the New Avengers. The Sentry and Ares joined Osborn's Avengers. Concurrently, Loki, masquerading as the Scarlet Witch, manipulated Hank Pym into creating a new team of Mighty Avengers.
- An interview with series writer Brian Michael Bendis on the Word Balloon Podcast said that the roster revealed in Wizard was not entirely accurate. Bendis stated that some of the members shown on the promo image would be on the team, while others wouldn't. Because of this, fans speculated on the roster, but the one as shown was used in the first issue, and on throughout the next 19.
- 90 appearance(s) of Mighty Avengers (Initiative) (Earth-616)
- 6 minor appearance(s) of Mighty Avengers (Initiative) (Earth-616)
- 14 mention(s) of Mighty Avengers (Initiative) (Earth-616)
- 70 image(s) of Mighty Avengers (Initiative) (Earth-616)
- 10 member(s) of Mighty Avengers (Initiative) (Earth-616)