The Liberators were formed by a coalition of terrorists from various countries, with the intent of defeating the Ultimates and taking over America. Its members were comprised of super-soldier experiments from the countries involved, each one designed to match and exceed the power of one of the Ultimates. Abdul Al-Rahman was designed after Captain America, Abomination after the Hulk, Crimson Dynamo after Iron Man, Hurricane after Quicksilver, the Swarm after the Wasp, and Perun after Thor. In addition, the ranks included the Schizoid Man, who had powers similar to the mutant Multiple Man, Hank Pym, who was angry at the Ultimates for firing him, and an army of foot soldiers, all equipped with a suit that gave them enhanced strength. However, this suit would kill the wearer after a period of 3 months. Loki, Thor’s half-brother, and the Norse God of Mischief, also had a major hand in the creation of the Liberators, for no reason other than to cause mischief.
The Liberators gained the necessary information to take down the Triskelion and the Ultimates using a spy inside the Ultimates ranks, who was eventually revealed to be the Black Widow. She first leaked information to the press, revealing that Bruce Banner was the Hulk that had attacked New York City previously. This led to Banner’s apparent execution, thus eliminating the Hulk. She then had Hawkeye’s wife and children murdered, and Hawkeye himself transported to a secret base of operations, where the access codes and other state secrets were taken from his head. Loki then altered reality to make it appear as if Captain America had led the attack. Nick Fury, upon watching the security tapes and seeing Captain America, immediately sends for his arrest.
The Liberators attacked the Triskelion first, and then Los Angeles and Washington, D.C. Though they appeared to have taken over the country in less than an hour (even pushing the Statue of Liberty into the ocean), Captain America and Hawkeye both escaped soon after, and a counterattack began, with even the Hulk appearing to help out.
One by one, the Ultimates killed their respective mirror members in the Liberators, except for Thor, who was still being held in the Triskelion. Eventually only Loki was left, and as a last-ditch effort called the beasts of Asgard to defeat the Ultimates. But the Scarlet Witch summoned Thor from his prison cell, and he proceeded to defeat Loki, banishing him presumably back to Asgard. The beasts Loki had sent were defeated by the Ultimates and the Knights of Asgard, sent by Odin.
Perun, the Soviet Thor, was next seen wandering New York City, trying to find someone to surrender to, as his allies all appeared to be dead. Hank Pym was arrested shortly after the battle ended, and the Black Widow was killed by Hawkeye as she recovered in a hospital room.