He is given the false identity John Harrison and coerced by Admiral Marcus into building weapons for Section 31 and Starfleet in exchange for the lives of Khan's crew.

According to the backstory revealed in the episode, Khan is one of a group of genetically engineered superhumans, bred to be free of the usual human mental and physical limitations, who were removed from power after the Eugenics Wars of the 1990s.

[2] Khan had been both the most successful conqueror and the most benign ruler of the group, ruling more than a quarter of the Earth's area across Asia to the Middle East from 1992 to 1996 with a firm but generally peaceful hand until he was deposed.

Captain Clark Terrell (Paul Winfield) and First Officer Pavel Chekov (Walter Koenig) of USS Reliant are searching for an uninhabited world to test the Genesis device, a powerful terraforming tool.

Twenty of the survivors, including McGivers, whom Khan had married, were subsequently killed by the only surviving animal life, the Ceti eel.

Swearing vengeance on Kirk, now an admiral, for abandoning them to die, Khan infests Terrell and Chekov with young Ceti eels; the creatures enter their brains, rendering them vulnerable to suggestion.

Kirk tricks Khan by using a special code to remotely lower Reliant's shields, allowing Enterprise to inflict significant damage.

Khan carries out an attack on a high level Starfleet meeting where Admiral Christopher Pike is killed before fleeing to the Klingon homeworld Qo'noS.

Khan crashes Vengeance in San Francisco in an attempt to destroy Starfleet Headquarters and escape, but is pursued and captured by Spock and Uhura.

She was ultimately stopped by Khan's own descendant, La'an Noonien-Singh (Christina Chong), alongside an alternate timeline version of James T. Kirk (Paul Wesley), who were sent back in time to preserve the course of history.

[3] Author Greg Cox penned three Star Trek novels featuring Khan, published by licensee Pocket Books.

"[9] The first draft of the script introduced the character as John Ericssen—who is revealed to be a man involved in "The First World Tyranny", named Ragnar Thorwald.

[8] In the original script, Kirk forgives Ericssen and offers him and his people a chance at a fresh start—something that remained in the final episode—but the character committing murder would have precluded such an ending, as NBC censors would have necessitated the "bad guy" be punished for his actions.

Author Paul Cantor asserts that Khan is a mirror image of Kirk, sharing his aggressiveness, ambition, and even his womanizing tendencies, but possessing them in far greater degree.

[17] Director Nicholas Meyer told Montalbán to keep Khan's right glove on at all times in order to give viewers a puzzle about which they could form their own opinions and add mystery to the character.

[18] Meyer has been repeatedly asked if Montalbán wore a prosthetic chest for his scenes, as his uniform was purposefully designed with an open front.

[20] Khan quotes the character of Ahab from Moby-Dick throughout the film, driving home his lust to make Kirk pay for the wrongs he has inflicted upon him.

[18] Following the box office success of J. J. Abrams' Star Trek reboot and the announcement that actors Chris Pine and Zachary Quinto had tentatively agreed to appear in two sequels, Internet rumors began circulating about the plot of the second film.

Abrams hinted that because of the alternate timeline created in the first film, reintroducing Khan into Star Trek lore remained a possibility.

'"[22] As part of the secrecy campaign, Benedict Cumberbatch denied that he was playing Khan during interviews, describing Harrison as simply a terrorist with his own purposes,[23] as well as "someone that's activated and manufactured in a way by Starfleet, and it's a scene that has come back to haunt him."

[24] Into Darkness writers Roberto Orci and Alex Kurtzman added that they used the character of Khan not just for his popularity with the fandom—"It's so easy to fall into the trap of doing something because you think people are going to love it.

In the Star Trek: Enterprise episode "Borderland", Malik, the leader of a group of "supermen" created from the same genetic engineering project as Khan, quotes Nietzsche, telling Archer that "Mankind is something to be surpassed".

[34] Though he felt that the villain of Star Trek: The Motion Picture, V'Ger, was more cerebral and interesting, author James Iaccino notes that most fans and moviegoers preferred the archetypical good-versus-evil fight that the struggle between Khan and Kirk represents.

[29] In 2002, the Online Film Critics Society's 132 members voted Khan as the 10th-greatest screen villain of all time, the only Star Trek character to appear in the listing.

[39] The character also had a cultural impact outside of Star Trek fandom; a clip from The Wrath of Khan featuring Kirk screaming "Khaaan!"

[45] Benedict Cumberbatch's performance in Star Trek Into Darkness drew praise from critics with Peter Travers of Rolling Stone magazine calling it a "tour-de-force to be reckoned with" and his character "a villain for the ages".

[47] Jonathan Romney of The Independent specifically noted Cumberbatch's voice saying it was "So sepulchrally resonant that it could have been synthesised from the combined timbres of Ian McKellen, Patrick Stewart and Alan Rickman holding an elocution contest down a well.

"[48] The New York Times praised his screen presence saying "He fuses Byronic charisma with an impatient, imperious intelligence that seems to raise the ambient I.Q.

[50] Star Trek: Voyager actor Garrett Wang tweeting, "The casting of Cumberbatch was a mistake on the part of the producers.