For additional meanings of "Klingon", please see Klingon.
Kor, 2266

A Klingon commander on Organia.

"A Klingon's honor means more to him than his life!"Kurn

The Klingons (Klingonese: tlhIngan) were a humanoid warrior species that originated from the planet Qo'noS (pronounced Kronos), an M-class planet. One of the major powers of the galaxy, the Klingons were a proud, tradition-bound people who valued honor and combat. The aggressive Klingon culture had made them an interstellar military power to be respected and feared. Klingons believed that they had the instinctive ability to look an opponent in the eye and see any intent to kill.

History and Politics


A clone of Emperor Kahless

Klingon cranial ridges dissolve

A Klingon's cranial ridges dissolving

The Klingon Empire was founded some time in the 9th century by Kahless the Unforgettable, who performed many heroic feats including the unification of the Klingon people when he killed the tyrant Molor. Kahless came to be revered in Klingon society to the point of near-deification, and many aspects of Klingon culture came to revolve around emulation of Kahless's life. (TNG: "Rightful Heir")

According to an early draft of "Rightful Heir", Data gave the exact date of Kahless's death as 1,547 years ago (from 2369), or AD 822. Also according to DS9: "Soldiers of the Empire", that the Earth calendar year of 2373 coincides with the year of Kahless 999.

The warrior ethos had been an important aspect of Klingon society since the time of Kahless, but the warrior aspects became much more dominant beginning in the early 22nd century. Previously, Klingon society was regarded as socially balanced, but over time the warrior caste gained greater prominence, to the point where the Klingons widely came to be regarded as a "warrior race." (ENT: "Broken Bow", "Judgment")

Because of their aggressive outlook, the Klingons generally had poor relations with other races after they began to move out into space. Because the worlds of the Klingon Empire were resource-poor, the Klingons developed an intense belief in the need for expansion and conquest in order to survive. The Klingons' relationship with Humans and the Federation was rocky at best. Following the disastrous First Contact between Klingons and Humans, tense rivalries and unavoidable conflicts often developed between the two races. (TNG: "First Contact"),

In the year 2154, the Klingons gained access to the genetic material of Human Augments and tried to adapt this genetic engineering to improve themselves. An unanticipated side effect was that the Augment DNA caused the characteristic Klingon cranial ridges to dissolve.

The test subjects did gain increased strength and intelligence, but then their neural pathways started to degrade and they died in agony. One of the subjects suffered from the Levodian flu, which was modified by the Augment DNA to become a fatal, airborne, mutagenic plague that spread rampantly among the Empire, from world to world. In the first stage of this plague, Klingons lost the ridges on their foreheads and began to look more Human.

With the help of a Klingon scientist named Antaak, Dr. Phlox of the Earth starship Enterprise was able to formulate a cure that halted the genetic effects of the virus in the first stage. This retained the changes in appearance along with some minor neural re-ordering. The neural ordering caused changes in the emotional make up of the Klingons. For example, the infected started to feel fear. Even though the infected did not develop any stage-two characteristics, such as enhanced strength, speed, or endurance they did not die from it. This left millions of Klingons changed. These alterations were even passed on to their children. (ENT: "Affliction", "Divergence")

The virus must have been cured before 2273 since we see Klingons with ridges in Star Trek: The Motion Picture. We also see other Klingons like Kang (lacking ridges in TOS: "Day of the Dove" thus having the virus. We then see him with forehead ridges in VOY: "Flashback" after he was cured. It should be noted, however, that Kang's and other like Klingon's ridges may be a result of surgical cranial reconstruction.
It is possible that at first the treatment only gave many Klingons a single ridge from the bridge of the nose across the forehead, and then was eventually perfected and allowed a complete return to the original form. This speculation comes from the fact that many Klingons seen during the 23rd century possessed rather minor ridges (such as Chang, Korrd, and Azetbur). Of course this could be simply the differences in appearance between Klingon sub-races.
It has been suggested that the disease afflicting the Klingons seen in VOY: "Prophecy", Nehret, is the modified Levodian flu. The Doctor manages to cure the Nehret using stem cells from B'Elanna Torres' daughter, who was ¾ Human and ¼ Klingon, suggesting a similar method was used to cure the Humaniform Klingons.

Klingons were apparently so embarrassed by the fallout from their failed attempt at genetic enhancement that they refused to discuss the incident with outsiders. Due to the secrecy of the Klingon Empire, knowledge of the change became lost over time to the general population of the Federation. By the 24th century, the reason for smooth forehead Klingons was not widely known outside the Empire, and questions were generally met with a brusque answer along the lines of "we don't discuss it with outsiders." (ENT: "Affliction", "Divergence"; DS9: "Trials and Tribble-ations")

It has been speculated that the events of the Temporal Cold War have complicated the "original" timeline of interstellar history. According to this theory, first contact between Earth and the Klingons was supposed to have occurred during the Augment Crisis of 2154, but the Temporal Cold War altered historical events, causing the contact to take place prematurely in 2151.

By 2223, relations between the Federation and the Klingon Empire degenerated to a point of unremitting hostility, which lasted for several decades. (Star Trek VI: The Undiscovered Country; TNG: "First Contact")

The lingering tensions between Klingons and humans continued to rise, eventually leading to the Battle of Donatu V near Sherman's Planet in 2245, and later erupted into what was considered the first Federation-Klingon War in 2267. This war was quickly ended by intervention by the Organians after only four days of fighting. (TOS: "The Trouble with Tribbles", "Errand of Mercy") Over the next several decades, an uneasy peace developed that was broken by brief but fierce skirmishes and conflicts (Star Trek III: The Search for Spock; Star Trek V: The Final Frontier). A true and lasting peace finally came in 2293 with the signing of the Khitomer Accords, thanks to the efforts of Chancellor Gorkon and the Human Starfleet officer James T. Kirk. (Star Trek VI: The Undiscovered Country) Since then, despite several periods of rocky relations (see Federation-Klingon War (2372-73)), the Federation and the Klingon Empire have been steadfast allies, especially in the face of Dominion aggression in the 2370s. (DS9: "By Inferno's Light")

Apocryphally, the game Starfleet Academy further explores the conflict between the Federation and Klingons in the years leading up to the Khitomer Accords. In the game, a series of border skirmishes are resolved when it is discovered that an unknown alien has been behind attacks on both Federation and Klingon border planets. This then helps to establish the foundation of the Khitomer talks.

The Klingon relationship with the Romulan people was also extremely unstable. A short-lived alliance and technology exchange notwithstanding, the Romulan Star Empire were typically regarded by the Klingons as a "blood enemy" since at least the 23rd century. Sporadic Romulan attacks against Klingon colonies (see Khitomer Massacre) and interference in Klingon affairs (see Klingon Civil War) continued to sour relationships between the two peoples. (TNG: "Sins of the Father", "Redemption II")

In the mirror universe, the Klingons were a founding race of the Klingon-Cardassian Alliance, where they formed an alliance with that universe's Cardassian counterparts. (DS9: "Crossover")

According to Daniels, the Klingons joined the Federation by the 26th century. (ENT: "Azati Prime")


"Even half drunk, Klingons are among the best warriors in the galaxy."

The Doctor

Klingon society was extremely complex. Before its decline in the mid 22nd century and again in late 23rd century Klingon society was based on a feudal system organized around traditional Great Houses of noble lineage, to which various parts of the population owed fealty. The Great Houses are traditionally represented in the Klingon High Council, which is led by a Chancellor.

The decline of Klingon culture is demonstrated in the acts of the Klingons themselves. They stopped caring about their weapons to the point that they let them rust (ENT: "Marauders") and even stopped caring for true honor (ENT: "Judgment"). Sometime after the augment virus took hold of the Klingon Empire a new regime took control turning the Empire into a fascist state that kept tabs on all who served. (TOS: "Errand of Mercy"). The old ways returned in the latter half to the 23rd and the first part of the 24th century.

Males traditionally dominated public life in the Empire, assuming the leading roles in politics and the military with only rare exceptions. (TNG: "Redemption") A notable exception to the prohibition of women serving on the High Council came when Azetbur became Chancellor of the High Council after her father, Gorkon, was assassinated in 2293. (Star Trek VI: The Undiscovered Country) Women, in turn, traditionally dominated the household and the management of the family's affairs. (DS9: "You Are Cordially Invited") Klingon women were treated as equals except in politics and matters of inheritance. They were prohibited by law from serving in the High Council and cannot take control of their Houses unless they have the money and no male successors of the lineage. Otherwise, Klingon women were expected to exhibit the same physical prowess and lust for blood and honor as the men.

Klingon society functioned through a system of family reputation and honor. Tradition was an integral part of their lives and breaking from observances was considered a grievous insult to society, an insult that is not forgotten easily. An offence usually brought shame to the offender's name for several generations. Bloodlines and relations were also taken very seriously by any "true" Klingon. Lines comprise of more than mere family members. (TNG: "New Ground")

An integral part of tradition was the various rituals that mark milestones in a Klingon's life or the history of the Empire. Most notable of the rites was the Rite of Succession, which a future leader of the Empire must complete with a valid Arbiter of Succession (Captain Jean-Luc Picard in the case of Gowron) overseeing the proceedings. Before the Rite can begin, there was another elaborate ceremony needed to confirm the death of the previous leader. This was known as the Sonchi ceremony. (TNG: "Reunion") Individual Klingon warriors were expected to go through the Rite of Ascension to be recognized as a full adult. (TNG: "The Icarus Factor")

Klingons were extremely territorial. According to the first known Klingon linguist, there was no such thing as an "insignificant corner of Klingon space". (ENT: "Bounty")



A typical Klingon male

The most distinctive feature of Klingon anatomy (except in those individuals afflicted with the Augment Virus) was a ridged forehead. The cranium was encased in an exoskeleton, which possesses a feature known as the tricipital lobe. (TNG: "Descent")

On average, Klingons were larger and physically stronger than Humans, though they possessed much less tolerance for cold weather. (VOY: "Displaced"; DS9: "Change of Heart") Spock said once that Klingons lack tear ducts, however Klingon myth states that Kahless once filled the ocean with his tears. (Star Trek VI: The Undiscovered Country; TNG: "Birthright, Part II")

Oxygenated Klingon blood usually appears red in a Class M atmosphere, however in Star Trek VI: The Undiscovered Country, Klingon blood appears pink/violet in one scene. It is possible this was done to keep the movie from being rated "R" in the US market. It is also possible that Klingon blood is "canonically" pink in color, because of what Colonel Worf said in The Undiscovered Country regarding the difference in Klingon blood compared to Human blood (after Colonel West, disguised as a Klingon, was shot down). On the other hand, with the sole exception of Star Trek VI, Klingon blood has always been red in every instance that it has been shown, including in Star Trek Generations and multiple episodes of all of the Star Trek television series. The pink color may also be a result of being exposed to a zero-G environment.
Marab's anatomy

The anatomy of a male Klingon afflicted with the Augment virus

Klingon anatomy small

The anatomy of a male Klingon without the Augment virus

Internally, Klingon anatomy was markedly different from that of Humans. There is a great deal more multiple redundancy in their organs, a principle they call brak'lul. This allowed Klingons to survive severe injuries in battle. They had twenty three ribs, two livers, an eight chambered heart, three lungs, and even redundant neural function and multiple stomachs. Some geneticists believed that the extra organs, notably the third lung, evolved to give Klingons greater stamina on the battlefield. Surprisingly, Klingons had relatively little knowledge of their own biology and their medicine is very poorly developed. This was largely due to their warrior traditions – a Klingon who is wounded was expected to be left to survive through his own strength, die, or to undergo the hegh'bat, a form of ritual suicide. (TNG: "Ethics"; VOY: "Lineage")

Klingon pregnancies normally ran thirty weeks, but with mixed species, gestation times were shorter. The odds against Klingon-Human conceptions were rather high; however, when successful, Klingon and Human metabolisms sometimes clashed, causing biochemical fluctuations in the mother, which may lead to fainting. Klingon traits remained dominant for several generations, even with a single ancestor; therefore, a child even ¼ Klingon still possessed forehead ridges if he or she carried the gene. (VOY: "Lineage")

Klingons had ridged spines, chests and feet. (TNG: "Ethics"; DS9: "Sons of Mogh"; ENT: "Broken Bow") After birth some Klingon infants experienced a pronounced curvature to the spine, which was correctable by surgery. This "defect" tended to run in Klingon families, especially among females. Federation medicine, fortunately, advanced beyond that, allowing an additional choice of treatment involving genetic modification. (VOY: "Lineage")

Klingon children matured far more quickly than Human children. At the age of only one Earth year, a Klingon child had the appearance a Human child had at about four. By the age of eight Earth years, a Klingon attained the maturity a Human did not reach until about age sixteen. (TNG: "Reunion"; DS9: "Sons and Daughters") When Klingon children began growing into adults, they went through jak'tahla, a Klingon form of puberty. (Star Trek: Insurrection) Like other mammalian species, Klingon females were capable of lactating to breast-feed infants. (TNG: "A Matter Of Honor")

Klingons tended to live for over 150 years, but even into advanced old age tended to still be strong enough for combat. (DS9: "Blood Oath")

Doctor Julian Bashir once sarcastically noted that the natural odor produced by Klingons was comparable to "vanilla with a hint of lilac". (DS9: "Trials and Tribble-ations")

Religion and Tradition


Ritual was a very important element in Klingon society. While the Klingons were not a religious people as such, they did believe that deities existed at one time. However, Klingon warriors supposedly slew their gods as they were considered to be more trouble than they were worth. (DS9: "Homefront") They believed that once a Klingon died, the spirit exited the body, leaving behind a worthless shell to be disposed of. (VOY: "Emanations") In the Klingon death ritual, it was traditional for those on hand to howl into the sky as a warning to the afterlife that a Klingon warrior was about to arrive. (TNG: "Heart of Glory"; DS9: "Tears of the Prophets") In some cases a funeral dirge was sung in memory of the deceased, or friends sat with the body to protect it from predators, a practice known as ak'voh. (DS9: "The Ship")

Furthermore, a Klingon who was unable to fight, and hence is unable to live as a warrior anymore, had the traditional obligation of committing the hegh'bat, which was the Klingon ritual suicide. Tradition dictated that the eldest son or a close personal friend must assist. That person's role was to hand the dying Klingon a knife so that he can plunge it into his heart, remove it, and then wipe the blood on his own sleeve. (TNG: "Ethics")

The Klingon afterlife was supposedly divided into two branches. The dishonored were taken to Gre'thor aboard the Barge of the Dead, a vessel captained by Kortar, the first Klingon. Kortar was supposedly the one who had originally killed the gods who created him and was condemned to ferry the dishonored to Gre'thor as a punishment. Once in Gre'thor, the dishonored were watched over by Fek'lhr, a vaguely Klingon-esque figure. While it may be tempting to view Fek'lhr as the Klingon equivalent of the Human devil, according to Kang, the Klingons have no devil. (TNG: "Devil's Due"; VOY: "Barge of the Dead"; TOS: "Day of the Dove")

Those who die honorably supposedly went to Sto-vo-kor, where Kahless was said to await them. However, should a noble warrior die in a manner that might not merit a place in Sto-vo-kor, such as being assassinated in a surprise attack, he may still earn a place if others dedicate a great battle to his name, thus showing that he has earned respect among the living. (TNG: "Heart of Glory", "Rightful Heir"; VOY: "Barge of the Dead"; DS9: "Shadows and Symbols")

Klingon rituals included the R'uustai, a bonding ceremony which joined two people together in a relationship similar to brotherhood. (TNG: "The Bonding") Klingon tradition holds that "the son of a Klingon is a man the day he can first hold a blade." (TNG: "New Ground")

If a Klingon warrior struck another Klingon with the back of his hand, it was interpreted as a challenge to the death. Klingon warriors spoke proudly to each other; they did not whisper or keep their distance. Standing far away or whispering were considered insults in Klingon society. (DS9: "Apocalypse Rising")

When going into battle, Klingon warriors often sang the traditional warriors' anthem, which was essentially an invocation to Kahless and a pledge to win a good death in battle. (DS9: "Soldiers of the Empire")

When choosing a mate, it is traditional for a female Klingon to bite the male's face, allowing her to taste his blood and get his scent. (VOY: "Blood Fever") Klingon daughters traditionally are given a piece of jewelry called a jinaq when they become old enough to select a mate. (TNG: "Birthright, Part II")

See also

Science and Technology


Klingon space

Food and Beverages



A list of all appearances of Klingons (excluding appearances of Worf and B'Elanna Torres).



Klingons were introduced in Star Trek: The Original Series, and first appeared in the episode "Errand of Mercy". At the time, they appeared as fairly ordinary Humans with heavy makeup and mustaches (although their appearance changed even within the original series, with dark makeup and heavy eyebrows being the norm, but the Klingons of "The Trouble with Tribbles" being much lighter-skinned and Human-like in appearance). Beginning with Star Trek: The Motion Picture, improved makeup techniques, and bigger budgets, led to their present elaborate forehead designs. The inspiration for the post-TOS Klingon make-up came from Planet Earth, a 1974 Gene Roddenberry pilot which starred Diana Muldaur and Ted Cassidy. That pilot featured a Klingon-inspired, warlike race of mutant Humans called the Kreeg who had ridges down the center of their foreheads.

After DS9: "Trials and Tribble-ations" made the change in appearance part of the canon, the Star Trek: Enterprise episodes "Affliction" and "Divergence" explained the differences.

Including Worf's appearances, the Klingons are the only non-Federation species to have appeared in all the movies. In Star Trek: The Motion Picture they attempt to attack V'Ger and are vaporised. They appear in the simulation of the Kobayashi Maru test in Star Trek II: The Wrath of Khan. They are the primary villains after the Genesis technology in Star Trek III: The Search for Spock. In Star Trek IV: The Voyage Home the primary vessel is a Klingon Bird of Prey and the Klingon Ambassador appears early on to have Kirk extradited. In Star Trek V: The Final Frontier, a Klingon Ambassador is featured again, on Nimbus III and they also appear as secondary villains as a young brash Klingon officer chases Kirk for the glory of defeating an infamous enemy of the Empire. In Star Trek VI: The Undiscovered Country, General Chang is the primary villain as a Klingon and they also appear throughout the film during the peace process of the Khitomer Accords. Finally in all TNG movies, Worf appears despite his commitments to Deep Space 9.

The only time the Klingon symbol is seen in the original series is in TOS: "Elaan of Troyius", and the high spire is actually facing right, not straight up as the subsequent versions are. Also, on the original Klingon ship model (the camera angles never showed it on the series), it was facing to the right there as well. It was probably meant to be that way originally, but series execs and concept designers likely found it looked better pointing straight up.

Note that the Klingons in Star Trek VI were given lavender blood specifically for ratings and plot purposes; Klingon blood on TV is red. Also, even individual Klingon makeup (Worf's head, for example) can change from episode to episode. According to David Alexander, in Star Trek Creator, a biography of Gene Roddenberry, Roc Books, 1994, the Klingons were named for Lieutenant Wilbur Clingan, a friend of Roddenberry who served with him in the Los Angeles Police Department.

Besides Michael Dorn and Roxann Dawson, the other Star Trek cast members who have worn the full Klingon makeup include Avery Brooks, Colm Meaney, Rene Auberjonois, Tim Russ, Kate Mulgrew, Ethan Phillips and Scott Bakula.

A story Robert O'Reilly tells in an interview in the DS9 Season 7 DVD, is that a long running joke among actors who have played Klingons, is that they do not want to appear in the films, as, he believes, that the only purpose of a Klingon in one of the films was to be killed off. He was proven right in Generations.

The infamous Klingon saying "Today is a good day to die" actually originated from the Lakotan warrior Crazy Horse.


In the novel Summon the Thunder, part of the Star Trek: Vanguard series, the Klingons who had a Human appearance (descendants of the victims of the Klingon augment virus) are referred to as QuchHa', or "the unhappy ones". They usually served in their own units although they also were known to mix with the rest of the fleet on occasion.

Popular Culture

On January 10th, 2007, Congressman David Wu made a speech on the House of Representatives floor referring to George Bush's staff as Klingons with regard to the Iraq War. Wu, an admitted fan of Star Trek, said he was making a reference to the title of James Mann's recent book Rise of the Vulcans: The History of Bush's War Cabinet (ISBN 0670032999). In the book, Mann writes that "Vulcans" is a nickname that President Bush's foreign policy advisory team in the 2000 campaign gave itself, originating from the large statue of the Roman god Vulcan in Bush adviser Condoleezza Rice's hometown of Birmingham, Alabama.

Wu said that unlike "the Vulcans of Star Trek", who "make decisions based on logic and fact", Rice and her cadre behave more like the warlike Klingons, saying, "there are Klingons in the White House". Wu continued that unlike "real Klingons", who are also known for their courage and code of honor, those in the White House "have never fought a battle of their own". He concluded "don't let faux Klingons send real Americans to war."

On 16 January 2007, comedian Jon Stewart dedicated a short segment of The Daily Show with Jon Stewart to talk about this speech. He was joined in this discussion by Leonard Nimoy and George Takei (Spock and Hikaru Sulu respectively). In the discussion Nimoy stated that the analogy was weak, citing that while Klingons are warlike, they adhere to a strict code of honor.

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