At a young age, Lex Luthor's parents were killed and he inherited their company. Growing up, he became interested in mechanics and patented many inventions. By his 20's, he was a corporate billionaire and built his company LexCorp into a financial powerhouse. WIth an array of technology, Luthor boasted having built Metropolis and two-thirds of its population work for him in one manner or another.
Lex Luthor lived his days as the city's most powerful and influential figure. That is, until Superman debuted and slowly won the love and admiration of the people. Around the same time, Luthor unveiled his LexoSuit, a billion dollar prototype. He was unable to sell a mass produced line to a client, the Regent of Kaznia, because of a US trade embargo. The two worked a secret deal. An elite squad of terrorists under contract with the Regent would steal the prototype and use it to reverse engineer it themselves. Luthor would then collect on the insurance and bank on the Pentagon would fear any country having a military advantage and contract him to build a better and more profitable suit.
Superman refused Luthor's offer to join forces, as he viewed Luthor as a criminal and vowed to stop him. Luthor concluded he would have to attain Superman's power in another manner and kill him. With his government contacts, Luthor funded Project Achilles, a black ops program dedicated to analyzing Superman. Achilles would be later absorbed into the much larger operation, Cadmus, years later. In the meantime, he pumped funds into LexCorp Research and Development to engineer his own weapon. LexCorp continued to survive through usual business deals and off the books sales to illegal arms dealers.
While unveiling a new museum dedicated to natural history, Luthor unknowingly held a shard of Kryptonite on display. When Superman tried to stop two common thieves, he fell ill. Luthor tried twice to kill Superman; luring him to a trap with a hired muscle and the more elaborate, a mechanical dinosaur. However, Superman remembered Professor Hamilton discovered lead could shield the radiation. Afterwards, Luthor greenlit a fervent search for samples of Kryptonite. For safe keeping, he always kept a shard by his side.
In another bid for a weapon to kill Superman, Luthor manipulated the terrorist, John Corben into undergoing an experimental surgery involving Metallo alloy, powered by Kryptonite. Though gifted with invulnerability and super strength, Corben was angered that he had lost his humanity in the process. As Metallo, Corben sought to kill both Luthor and Superman and failed.
After Superman's run in with the mechanical dinosaur, LexCorp technicians collected Superman's blood. Luthor used the DNA to start a secret cloning laboratory outside of Metropolis. Generic memories were programmed into the first clone. Luthor sought to control an army of cloned Superman's. However, the cloning process was flawed and the first mutated into what became known as Bizarro. Luthor abandoned the facility and detonated the half kiloton payload to cover his tracks.
Luthor also took advantage of former employees' desire for revenge on Superman, including Edward Lytener. Luthor gave Lytener technology and access to LexCorp's satellite communications. Lytener created a red sun environment that stripped Superman of his powers. After the event passed, Luthor used the data to create red sun lamps that supplied Project Achilles with in the future.
In an unconventional alliance, Luthor hired the Joker to kill Superman for a billion dollars. Luthor gave him access to his various facilities but Batman tracked Joker to Metropolis and intervened. The Joker cut his losses by kidnapping Luthor and hijacking his LexWing aircraft. Joker set out to destroy everything Luthor built, Metropolis. Batman and Superman freed Luthor and stopped the Joker, who narrowly escaped death, once again.
After avoiding an connections to the Joker, Luthor attempted to rebound with the debut of the LexCorp Sky Sentry, a defensive tool that utilizes a high powered magnetic beam designed to knock out guided missiles. One of Luthor's previous ambitions resurfaced. Brainiac had uploaded a copy of itself into LexCorp's systems during its stay on Earth. It quickly took control of LexCorp's R&D Lab in Sector Six and sought to build itself a new body. However, Brainiac needed Luthor's technical skills to put the finishing touches. It sabotaged the Sentry and lured him to the labs. Superman, as Kent, was able to convince Luthor's assistant, Mercy, to investigate his sudden reclusiveness. Brainiac was discovered but before the lab imploded on him, it blasted another copy of itself into Luthor. Since Brainiac was reconstructed with LexCorp technology, Luthor was able to legally confiscate the remains for research.
In another project aimed at creating and controlling a Superman-esque person, Luthor debuted the fruits on one-time engineer, John Henry Irons, the LexCorp Police Battlesuit Series Alpha. Irons' concern over the flaw in the neural interface was ignored. Luthor was confident in the override failsafe. It ultimately failed and Superman was forced to use high voltage to short circuit the suit and wearer, Sgt. Corey Mills.
Superman and Batman were not the only heroes to earn the animosity of Lex Luthor. It turned out that LexCorp explosive tests being conducted off of the eastern seaboard were encroaching on Atlantis. The city's ruler, Arthur, better known as Aquaman, went to the surface and tried to stop the tests. Aquaman was detained at an aquarium until he was discovered by Lois Lane.
When Superman was brainwashed by Darkseid and arrived on Earth leading an invasion force, Luthor supplied Project Achilles with a Kryptonite-lined warhead. Supergirl and Superman were knocked unconscious and taken to a top secret facility and tried. Luthor's red sun lamps kept Superman and Supergirl in check. Luthor wanted to take advantage of the situation and kill Superman with a lethal injection of liquid Kryptonite. Lois Lane infiltrated the facility and freed the two.
Years later, the Justice League formed a sting to take down Luthor once and for all. J'onn J'onzz, disguised as Superman, confronted Luthor. Playing the part, J'onn managed to get Luthor to reveal he bribed shipping magnates and Interpol agents in order to sell weapons to terrorists. Luthor escaped the League and led Superman on a high speed chase until he suddenly suffered a seizure. It turned out that Kryptonite affects humans over a longer period of time in the form of terminal blood poisoning. Luthor was taken to Stryker's Prison but he plotted a last ditch plan to kill the League before his imminent death. With Ultra-Humanite's expertise, Luthor escaped and formed the first Injustice Gang. After failures began to stack up, Luthor paid Humanite more to create a containment unit to stabilize his condition. Luthor then donned a battlesuit capable of firing Kryptonite blasts. Luthor continued to try to kill the League but failed time and time again.
Luthor was given the opportunity to clear his record with a presidential pardon, when the League faced the Justice Lords. Luthor used his Power Disrupter to permanently strip the powers and abilities of the Lords through neural manipulation. Though Mercy Graves was entrusted as the new CEO of LexCorp, Luthor was still clearly in control. One of first acts was to write a book about his experiences called "Into The Light." Lex Luthor allied himself with Cadmus, a government program with goals of attaining defenses against the League. He provided off the books funding as he did with Achilles. Luthor also spent $75 million on a false presidential campaign to influence a chain of events aimed to provoke a confrontation between Cadmus and the Justice League. He even created Lexor City, a self-proclaimed utopia, within Metropolis, that would provide free energy and housing to the needy. It was another front to publicly discredit Superman and the League. The plan involved Superman dismantling an experimental Sryptonite fusion generator under the ruse it was a bomb. The plan fell through and more. Captain Marvel tried to stop Superman and battle was videotaped live.
After a physical conducted by Professor Hamilton, Luthor was shocked to learn his Kryptonite induced cancer was completely gone from his system and that he had the body of a fit 20 year old. Hamilton concluded it was a side effect of his vest or the Kryptonite poisoning itself. Luthor found himself gifted with super strength.
Lex Luthor apparently managed to hack into the JLU Watchtower and remotely activate the binary fusion cannon and blasted it into a Cadmus compound that was just relocated after Superman and Huntress infiltrated it. Because of this, the US government suspected the JLU of this crime since it also leveled a nearby city. It prompted Amanda Waller to launch an all out attack on the JLU. Meanwhile, Luthor was free to finish building a mysterious project of his, an android body based off of Professor Ivo's AMAZO android. Before he could transfer his brain into it, Amanda Waller destroyed it with a Nano-Disassembler Gun; ironically of Luthor's design.
The founding members of the JLU arrived and along with Waller, watched as Brainiac manifested itself from within Lex Luthor. Luthor was the unknowing vessel for a copy of Brainiac. Years ago when he was hel captive by Brainiac, it embedded a nano copy into Luthor and it bidded its time. Being the businessman, Luthor took this as the last chance to acheive his ultimate goal; power, knowledge and immortality. He managed to appeal to Brainiac, and the two set out to become gods. After assimilating the abilities of the Dark Heart, they created a machine that would allow them to assimilate a planet in one shot. After destroying everything in the universe, Luthor convinced Brainiac they would use their knowledge and power to remake the universe and be its god. However, they were stopped by the Flash. Flash used lightspeed vibrations to destroy Brainiac but Luthor was unscathed and taken back to prison.
After spending nearly a year in prison, Lex Luthor became detached. Prison officers observed him talking to himself and not showing any hostility or emotion. While being transferred, Luthor made a move and hijacked the prison van transporting him. It seems he is either suffering from delusions or still retains a limited mental bond with Brainiac. Nonetheless, Luthor was saved by the Key. The Key took him to a secluded swamp where Grodd revealed himself and his operation. Luthor declined Grodd's offer, until Grodd revealed he had the last piece of Brainiac on the planet. Luthor obliged and works for the Legion. Luthor's first test was to go to Blackhawk Island with the Key and Dr. Polaris and steal the Spear of Longinus. Their efforts were opposed by Shayera Hol, Flash, Fire and the last Blackhawk, Chuck Cuidera. However, Luthor set the self-destruct program and fled with his partners and the Spear. Grodd was impressed and assured him his next mission would be the real deal.
In the meantime, Grodd assigned Luthor to begin augmenting the powers and abilities of select Legion members. He gifted Devil Ray with increased strength, Killer Frost with pyschokinetic control and Atomic Skull with radioactive projection. When the Viking Prince's corpse was unearthed, Grodd devised a plan to take the body for himself. Luthor would then reverse engineer the Prince's invulnerability and bestow it upon every member of the Legion. The theft failed.
Lex Luthor was assigned to build Grodd a suitable amplifier for a carrier wave. Luthor was led to believe it was for Grodd's mind control module. The amplifier required a power source though. Grodd sent Luthor and several others to the Himalayas to steal the Heart of Nanda Parbat, a mystical totem. With it, the souls of the Temple's monks were taken. Grodd then led a larger group of super villains to Gorilla City to use their shield generator to spread the waves of de-evolution. However, Grodd's master plan was thwarted by Batman, Superman and Wonder Woman. Luthor was irritated by Grodd's plan and shot him unconsious back at Legion headquarters and assumed leadership.
Time and time again, Luthor failed to reconstitute Brainiac. In the meantime, he was charged with satisfying the demands of his peers. Luthor devised a plan to steal millions of Euros being delivered to Kasnia, only to switch bodies with the Flash. He also hacked the Justice League communications links to provide a bankrupt Roulette with attractive fighters. In any case, Luthor's unstable behavior warrants the concern of many within the Legion. Tala tapped into the psychic memory of the piece of Brainiac and revealed to Luthor that it still existed in a distant galaxy. Luthor reconfigured the headquarters' cloaking field into a hyperspatial drive. However, Tala engineered a rebellion by freeing Grodd from his prison. Tala attempted to confront Luthor, but he possessed the Eye of Agamotto, an ancient artifact capable of amplifying the mind's eye and in turn, gifting its possessor with psychic abilities. After the short lived mutiny, Luthor captured Tala and used her as a mystic conduit to siphon Brainiac's essence and reconstitute it. Luthor was unaware that remnants of Darkseid were also present. Instead of Brainiac, Darkseid returned and destroyed the headquarters. Luthor and a small group of survivors made their way to the Justice League Metrotower on Earth to reveal what had happened.
Luthor desired to get revenge on Darkseid by temporarily allying with the JLU. During battle, Luthor re-encountered the New God, Metron. He managed to convince Metron to help him attain the one thing that could stop Darkseid, the Anti-Life Equation. Together, they journeyed to the Source Wall, at the edge of the universe, where the Equation lay. Luthor managed to survive breaching the Wall and returned to Earth to stop Darkseid. In an explosion, Luthor and Darkseid disappeared. Whether both survived or not is unknown.