Developed by screenwriter Gene L. Coon in 1967 for the original Star Trek (TOS) series, Klingons were humanoids characterized by prideful ruthlessness and brutality.

Hailing from their homeworld Qo'noS (pronounced approximately as /kho-nosh/, but usually rendered as /kronos/ in English), Klingons practiced feudalism and authoritarianism, with a warrior caste relying on slave labor and reminiscent of Ancient Sparta.

With a greatly expanded budget for makeup and effects, the Klingons were completely redesigned for Star Trek: The Motion Picture (1979), acquiring ridged foreheads.

Initially intended to be antagonists for the crew of the USS Enterprise, the Klingons became a close ally of humanity in Star Trek: The Next Generation.

They were named after Lieutenant Wilbur Clingan, who served with Star Trek creator Gene Roddenberry in the Los Angeles Police Department.

The swarthy look of Klingon males was created with the application of shoe polish and long, thin moustaches; budget constraints limited creativity.

[4] The overall look of the aliens, played by white actors, suggested orientalism, at a time when memories of Japanese actions during World War II were still fresh.

[5] Klingons became the primary antagonists of the Enterprise crew, in part because the makeup necessary to make another alien race, the Romulans, was too time-consuming and costly.

To give the aliens a more sophisticated and threatening demeanor, the Klingons were depicted with ridged foreheads, snaggled and prominent teeth, and a defined language and alphabet.

New costumes were fabricated, retaining the air of feudal Japanese design; Fletcher thought it was an important part of the Klingon authoritarian attitude.

Westmore designed his Klingons' beards to be Elizabethan, combining prehistoric and aristocratic elements to give audiences a feeling of depth from the appearance.

[6] The Next Generation effects artist Dan Curry used his martial arts experience to create a flowing fighting style for the race.

Curry combined elements of the Himalayan kukri, Chinese axes and fighting crescents to create a two-handed, curved weapon that has since been widely used in the franchise.

[16] The culture of the Klingons began to resemble revised western stereotypes of civilizations such as the Zulu, the Spartans, the Vikings, and various Native American nations—as a proud, warlike and principled race.

[19] The Klingons were given new uniforms designed by Dodie Shepard, in part because there were not enough of Fletcher's The Motion Picture costumes to meet the demands of the film.

[21] Dorn described playing a Klingon as simple, joking that after hours sitting in a makeup chair, actors were highly motivated to get the dialogue right the first time.

[22] Todd Bryant (Captain Klaa in Star Trek V: The Final Frontier) similarly noted that if an actor was projectile-spitting on others as he spoke Klingon, he was doing a great job.

"[27] A canonical explanation for the change was given in a two-part storyline on Star Trek: Enterprise, in the episodes "Affliction" and "Divergence" that aired in February 2005.

[31] In the non-canon video game Star Trek Online, Klingons under the command of Ambassador B'vat once again attempt to fuse the DNA of other races with their own.

Their anatomy is redundant and supernumerary; every organ has a backup, including an extra set of kidneys, an eight-chambered heart, a third lung, a secondary brain stem, as well as an extensive and hardy skeletal structure.

All of this makes Klingons extremely hardy and difficult to kill, as necessitated by their aggressive nature, and resistant to physical trauma, environmental exposure, and illness.

Klingon children are fierce and aggressive by nature; from as soon as they can walk, they are instructed into honing their hunting and combat skills, strengthening their physical prowess and agility.

[32] The Klingons adhere to a strict code of honor, similar to feudal Mongolian or Japanese customs, although some, such as Gowron, appear to struggle to live up to their ideals.

For The Motion Picture, James Doohan, the actor who portrayed Montgomery Scott, devised the initial Klingon-language dialogue heard in the film.

[36] For The Search for Spock, Marc Okrand, who created the Vulcan dialogue used in the previous film, developed an actual working Klingon language based on Doohan's original made-up words.

[39] The language does not contain the verb "to be", which meant Okrand had to create a workaround when director Nicholas Meyer wanted his Klingons to quote Shakespeare and the famous line "to be, or not to be" in The Undiscovered Country.

[44] In May 2009, a joint collaboration between the KLI, Simon & Schuster, and Ultralingua launched the Klingon Language Suite for the iPhone concurrent with the release of the new movie.

The film Star Trek VI: The Undiscovered Country established the name as Kronos; Okrand later devised the Klingon transliteration "Qo'noS".

It includes a lone, huge land mass with a vast ocean, a severely tilted axis that causes wild seasonal changes, a turbulent atmosphere and extremes of both warm and frigid weather.

[51] The planet is also home to the Capital City of the Klingon Empire, which features prominently in several episodes of The Next Generation and Deep Space Nine.