Iron Legion

The Iron Legion was created after the events of The Avengers. After Tony's near death experience and battle with the Chuitari and Loki, he realized that Iron Man couldn't do it all on his own, that he needed an Iron Legion. He began creating many suits, first each one getting more and more upgraded, but then realizing that one suit couldn't do it all so he began having one suit, or series of suits specialize at one thing, such as Stealth, Construction, Fighting, Flight, etc.

History
After New York, Tony began building an Iron Legion and expanded it to no limit.

Iron Man 3
He was working on the Mark 42, which was going to be the next member of the Iron Legion. After his house was destroyed and the president was kidnapped, Tony ordered the "House Party Protocol," which activated all the Iron Man Armors back at what remained of his house. They then met up with him on a oil rig in Florida, where The Mandarin planned to kill the president on live TV. Tony ordered the suits to attack all Extremis soldiers, which they did. Hammerhead dove right into a group of Extremis soldiers. Bones then split itself to its basic components and hit several soldiers, sending them falling to their deaths. Meanwhile the Extremis soldiers rip off Hammerhead's head and arms, causing it to fly and spin out of control, crashing into the oil rig. The rig would have fallen, but Igor came and lifted it back up. The battle continued between the Extremis soldiers and the suits. Red Snapper was covered in Extremis soldiers, so Tony ordered Heartbreaker to help him out. Heartbreaker killed all but one Extremis solder, who ripped off his face, sending Snapper into the oil rig, making a huge explosion and trapping Pepper. Silver Centurion then came onto Tony and Heartbreaker picked up Rhody and the two flew off to find Pepper. However, a Extremis soldier jumped onto Heartbreaker, forcing it to let Rhody go. 2 Extremis soldiers were about to attack him, but Thumper came and smashed the ground, sending the 2 flying. He then punched them into the air and another suit shot them. Tony then found Pepper, but Killian came and overheated Silver Centurion, thus making it useless. Meanwhile, 2 Extremis soldiers try throwing steel bars at a suit, which simply blasted them. Tony called for another suit, which Bones came to respond, however, just as Tony was about to jump into it, another soldier jumped onto Bones. Rhody rescued the president and left, letting the Iron Man suits to finish the job. After Pepper fell into the fire, Tony put on Nightclub and fought the Mandarin, who ripped off the suits arm and punched right through it, but Tony ejected himself into Shot Gun. After a brief fight on the roof, Killian sliced the suit in half, but Tony again ejected out in time. Just as he is about to kill Tony, the Mark 42 comes to the fight and Tony wraps it around Killian and self destructs it. Tony then jumps off and part of another Iron Man suit comes and just saves Tony, but crashes to the ground. Killian then reveals that he survived and is about to attack Tony, claiming himself The Mandarin, when the Pepper, who survived because of the Extremis added to her, comes and smacks him away with a poll. The Mark 10 then comes and mistakes Pepper for a Extremis soldier and blast her. Tony tells it that she is not a target, but his communicator was knocked away. Pepper then punches through the suit and uses it's Replsors to kill The Mandarin once and for all. J.A.R.V.I.S. then reports that all Extremis soldiers are killed and Tony orders the "Clean Slate protocol" which self destructs all remaining suits (20 suits are shown exploding).

Members
There are 35 total members of the Iron Legion.

Suit Types
Stealth Suits:

Mark XII

Sneaky Night Club

Casanova

Disco

Construction:

Striker/Thumper

Gamma

Fiddler

Igor

Artillery:

Heartbreaker

Casanova

Romeo

Speed/Distance:

Tiger

Python

Midas

Shot Gun

Gemini/Starboost

Fighting:

Hot Rod

Peacemaker

Tank

Radiation:

Gamma

Jack

Silver Centurion:

Blue Steel

Silver Centurion

Trivia

 * The Mark 7 armor may have been in the Iron Avengers as it was in use at the time of their construction.
 * The Wine Cellar they are kept in was built by Igor
 * In the promotional poster, Nightclub, Heartbreaker, Tank, Silver Centurion, Bones, Shot Gun, and the Mark 42 can be seen.
 * In the promotional items, the Heartbreaker, Thumper, Silver Centurion, Bones, Igor, Shot Gun, Hammerhead, Peacemaker, Red Snapper, Gemini and Mark 42 were the most used Armors.
 * Despite Gemini's high profile, it had nearly no screen time in the movie
 * Igor may still be functioning, as if he was destroyed the rig would have collapsed.
 * Only 20 suits are shown exploding during the "Clean Slate Protocol," 2 are shown to be destroyed by Extremis soldiers, the Mark 10 smashed by pepper, Igor held up the oil rig, and 4 suits were destroyed by the Mandarin. 7 others are missing, presumedly destroyed by the Extremis soldiers during the battle.