Justice League

The Justice League was formed after the invasion of the imperium (White Martians) by the seven heroes who responded to the catastrophe. The team was converted after the thanagarian invasion into the Justice League Unlimited. The League's first headquarters was in the Watchtower I, and after its destruction has given the same name to all of the leagues following bases.

The Imperium invasion and formation
Following Darkseid's invasion of Earth, Superman regained the majority of the world's trust after being brainwashed and used as a pawn. Though doubts remained regarding the Man of Steel's reliability, none put more faith in the hero than Senator J. Allen Carter. Carter proposed world peace through weapons disarmament, and nominated Superman for the job. Though skeptics aired their grievances, the World Assembly passed the motion and Superman set to work. As Superman finished disarming the weapons of destruction, meteors rained down upon Earth. From the wreckage, massive alien creatures appeared, and without hesitation made their intentions clear: conquest. Superman and Batman rushed to the scene, throwing everything within their arsenals at the creatures but their efforts seemed in vain. As the world panicked about the newest alien invasion, Superman fled the scene. Batman tracked the hero to a US Government base. Investigating further, the two discovered a different alien held prisoner there. Freeing him, the man introduced himself as J'onn J'onzz, but the newly-formed trio quickly found themselves under attack by the Imperium. The trio was still outnumbered, but not for long. At a critical moment, the Green Lantern John Stewart, Hawkgirl, Wonder Woman, and the Flash arrived on the scene. The Imperium forces fought back, but they lost; Earth's heroes had assembled. J'onn explained the Imperium Invasion. The septet then broke into three groups, each set on destroying the Imperium factories created on Earth. The heroes fought valiantly, but to no avail. The Flash and Green Lantern made a hasty retreat, while Superman and Hawkgirl were captured. J'onn, Batman, and Diana discovered a method to defeat the Imperium, but in the end only Diana and J'onn escaped. The four remaining heroes regrouped at Metropolis, and prepared to free Hawkgirl and Superman. Keeping a relatively low profile, the heroes managed to subdue the few Imperium forces to cross their path, but eventually were captured as well. Reunited with their friends (albeit via captivity), the heroes were shocked to discover the Imperium organizer to be none other than Senator Carter. The real J. Allen Carter had perished on Mars during a space expedition. Using his persona to their advantage, the Imperium tricked the world into disarming itself. The Earth disarmed, no obstacles remained to prevent their invasion. Earth's heroes, however, proved too resilient. Batman freed the other six, and the group destroyed factories and armada. In the aftermath of the invasion, Batman built and the activated Watchtower, set to orbit around the Earth to act as an early warning system. The heroes recognized the Earth's need for protection, and the Justice League formed.

The Justice League
Though the team had formed, threats continued to face both the world and the galaxy. At each turn, the team faced greater and greater challenges; however, their combined strength continued to prevail. Combining their strength, however, was no easy task. The team rarely worked as a collective group. Often times members would place personal goals over those of the League and the Earth. Each member had his or her own method for dealing with criminal activity: Superman and Wonder Woman, for example, embodied a "shoot first, ask questions later" approach, while Batman and John Stewart preferred concrete evidence and planning to blindly throwing punches; Hawkgirl and J'onn J'onzz often had difficulty empathizing with humanity. At times, their differences caused the team great turmoil, and the group nearly split on several occasions (Gorilla Grodd having the most success with his Secret Society). Despite their differences in approach and definition of heroism, they slowly learned to trust one another. For example, though Batman and Superman never completely saw eye to eye, in a small tribute to the (presumed) deceased Man of Steel, Batman admitted he had nothing but respect for the hero's approach and ideals. The two often bickered, but the interaction between John Stewart and Hawkgirl fostered a romantic relationship. Diana grew more accepting of "man's world" and had something of a romantic fling with Batman. The League, however, would not face its greatest challenge until the invasion of the Thanagarian military; not only was another alien force threatening Earth, but the League was also betrayed by one of their own.

The Thanagarian invasion
The Thanagarians came to Earth claiming to be there to defend it from the Gordanians, who had seemingly just attacked Washington D.C. It was revealed at this time that Hawkgirl, who had previously claimed to be on Earth by accident, was sent here by the Thanagarian government as an advanced scout. She also revealed to GL that she was engaged to Hro Talak, the leader of the Thanagarian forces on Earth. Batman soon discovered that Hro Talak and the Thanagarian army staged the Gordanian attack. Shayera was torn between her loyalties to the League, and to her people. Not knowing what her people were truly up to, she betrayed the League and used her knowledge of their weaknesses to help her people imprison them. After the League escaped, Shayera learned that the Thanagaians' plan would lead the Earth's destruction. She again switched sides and aided her former teammates in stopping Hro from completing his mission. At the cost of the Watchtower, Batman destroyed the Thanagarian machinery. Filled with self-doubt and knowing many people would never trust her again, Shayera resigned from the Justice League.

The Reformed League
With the loss of the Watchtower and a founding member, the League underwent a major change. A new Watchtower was built, along with an entire fleet of Javelins. The biggest change, however, was the expanded roster: nearly all of Earth's heroes, as well as some from other worlds, joined the new Justice League. In addition, the team made particular efforts to recruit Green Arrow as their political conscience, especially in anticipation of the team facing temptations that could corrupt them into an equivalent of the Justice Lords. Eventually, Shayera Hol even returned, albeit without the Thanagarian armor she'd worn as Hawkgirl. J'onn also changed his role within the League, staying on the Watchtower and assigning missions to the other members, rather than being an active combatant. The original members of the Justice League served as an inner leadership council, with Superman being regarded as first among equals.

Still, the power the League represented made many in the United States government uncomfortable. Amanda Waller was made head of Project Cadmus, an agency designed to make counter measures in the event the Justice League went rogue. To avoid any scandal, the agency was formed without Congressional approval and secretly funded by Lex Luthor. Unknown to anyone, however, Brainiac was manipulating Lex Luthor to use Cadmus as a distraction while he attempted to build himself an android body that he could inhabit. Eventually, Luthor, Waller and General Wade Eiling shifted Cadmus' agenda from counter measure to provoking the League into a confrontation.

The Cadmus crisis and the Legion of Doom
Learning of Cadmus, Batman had the Question try to find the link between Luthor and Cadmus. Question was captured by Cadmus, but rescued by Superman which required using force against US military personnel, including Captain Atom. Afterward, the League debated directly attacking Cadmus, but Green Arrow was arguing effectively that option was excessive and the government had the right in principle to have countermeasures in case the team went rogue like the Justice Lords did. Before a consensus could be reached, Luthor then secretly seized control of and fired the Watchtower's Binary Fusion Generator at the Cadmus base, making it appear to be retaliation, causing massive collateral damage to the surrounding city. To ease tensions, the original members of the Justice League (minus Batman) surrendered themselves to the United States government. At the same time, Cadmus launched an unauthorized assault against the Watchtower, while Batman persuaded Waller to investigate Lex Luthor. Discovering that Luthor had fired the weapon, Waller and the original seven members of the Justice League went to confront Luthor and destroyed the android he had been making. Out of options, Brainiac emerged from within Luthor and managed to escape. Luthor proposed a an agreement, where by they would merge and share the best of each other: Brainiac's knowledge and Luthor's imagination. The Luthor/Brainiac hybrid was defeated and Brainiac destroyed by the Flash. In response, Project Cadmus was terminated.

Following the Cadmus incidents, the League also built the Metro Tower in an effort to make themselves seem more down-to-Earth. At the same time, Gorilla Grodd formed a new Secret Society to help supervillains counter the "threat" of the Justice League. Unfortunately for Grodd, he brought Lex Luthor into the group. Luthor usurped command from Grodd and used the group's resources to try and resurrect Brainiac, accidentally resurrecting Darkseid, Lord of Apokolips, who launched an invasion of Earth in revenge against Superman. Facing a full scale invasion, the Justice League mobilized its entire roster and allied with the Secret Society. Lex Luthor managed to stop Darkseid with the Anti-Life Equation, and the supervillains were allowed a five minute headstart before the League went after them.