When you think of Star Trek aliens, two interstellar races probably spring to mind first: the Vulcans, those pointy-eared logicians, and their polar opposite, the Klingons. The warrior race has served a lot of different roles on Star Trek over the decades. First, they were the Federation's enemies in a long-running Cold War, as if they were the Russians to Starfleet's United States. Then, they became the Federation's allies. They went from being hotheaded killers to noble warriors. And somewhere along the line, especially on Deep Space Nine, they became the alien embodiment of the human Id.
The Klingons also happen to play a huge role in Star Trek Into Darkness. So, in their honor, we've rounded up eight milestones of Klingon history and culture that sum up why we love them so much.
1. Their Introduction: Meet Kor — "Errand of Mercy"
The Klingons made their debut in the Season 1 episode of The Original Series called "Errand of Mercy." Insanely warlike, they led an invasion of Organia, a planet inhabited by simple peasant dwellers. Or so they thought. The head of their occupation force was Kor, a mustachioed menace who was a lusty foil for Kirk. Kor was portrayed by John Colicos, and awesomely enough, this first encounter wouldn't be the last time we'd see him in the role.
2. Picking a Fight With Scotty — "The Trouble With Tribbles"
What was unique about the Klingons from the start, on The Original Series, was their capacity for getting under humanity's skin. Just look at how easily this one Klingon picks a fight with Scotty. All he has to do is call the Enterprise a "garbage scow." Maybe it's because the Klingons hit so close to him. To 23rd century humans, they're humanity as we used to be — aggressive, militaristic, incapable of overcoming our passions. And they're probably what we're still like here in the 21st century, except that we don't like to eat gagh. (That'd be worms, for those of you don't speak Klingon.)
Oh, you're also probably wondering about their physical appearance in The Original Series. Now we know from all later representations of Klingons that they have serrated forehead ridges. So why didn't they in the '60s TV show? Um, hello, lack of budget. But there is an in-universe explanation. The Klingons' experimentation with Earth-style genetic engineering in the mid-22nd century caused a whole swath of their population to end up looking more or less human. The idea was to use some of these human-looking Klingons to infiltrate Starfleet, but the mutation went viral and ended up affecting much of Klingon society.
3. "You Klingon Bastards..." — Star Trek III: The Search for Spock
The Klingons, though formidable, were a little oafish on The Original Series. Boy, did that change in Star Trek III: The Search for Spock where one Klingon in particular, Christopher Lloyd's Commander Kruge, came to represent just how fearsome the warrior race could be. He had Kirk's son, David, killed in an attempt to wrest Project Genesis out of his grasp. That led to William Shatner's immortal "You Klingon bastard, you killed my son!" monologue. Kruge was so formidable that the only way Kirk could defeat him was by blowing up the Enterprise — the moment after Kruge's crew had beaned aboard the exploding ship, of course. And even then Kirk only killed Kruge by throwing him into a pit of hellfire.
4. Worf — Star Trek: The Next Generation/Deep Space Nine
So after their villainy crescendoed in The Search for Spock, it was a surprise that Gene Roddenberry decided to make the Klingons allies of the Federation on Star Trek: The Next Generation. Symbolic of this detente was the presence of the first-ever Klingon Starfleet officer: Michael Dorn's Worf. Now Worf was a Klingon orphan raised by human parents in Belarus, so he was something of an outcast from his own people while also being a misfit among humanity. That made him, along with Brent Spiner's Data, Next Generation's "outsider on a quest," as Spock had been on The Original Series. He's more martial than many of the humans on the show, and he certainly loves a good fight. But he's entirely a noble warrior. Unlike the party-down, Bacchanalian sensibility of other Klingons we see in on Next Generation and Deep Space Nine, Worf is buttoned-down and stoic, a walking mass of awkwardness. Which makes us love him all the more.
5. Klingon Justice — Star Trek VI: The Undiscovered Country
The final movie featuring the entire Original Series cast showed how exactly the Klingons and Federation made peace. It came out in 1991 and is pretty obviously an allegory for the end of the Cold War. But the two sides didn't patch things up without a little drama beforehand: most notably, the assassination of the Klingon chancellor Gorkon (David Warner), for which Kirk and McCoy had to stand trial. Just check out that Klingon judge's gavel! Is that the scariest thing you've ever seen or what?
6. "The Way of the Warrior"
And even decades into the Federation-Klingon Empire peace accords, tensions could still flare up. In fact, things reached a boiling point in the Season 4 premiere of Deep Space Nine, "The Way of the Warrior," in which the Klingons attack the titular space station after accusing Starfleet's Captain Sisko of protecting the Cardassian Empire's leadership council. (The Klingons and Cardassians had been at war, yada yada yada.) Alliance be damned, the Klingons would attack and board Deep Space Nine in order to abduct the Cardies they wanted. Chancellor Gowron tells DS9's Captain Sisko, when the good captain talks about how formidable his space station is, "You're like a toothless old Grishnakh cat trying to frighten us with your roar!" Only a scenery-chewer like Avery Brooks could compellingly deliver the response to that: "I can assure you this old cat may not be as toothless as you think."
7. Kor's Exit — "Once More Unto the Breach"
Star Trek fans' entire decades-long relationship with the Klingons came full circle when John Colicos, who played Kor way back in "Errand of Mercy" in 1967, returned in 1998 to play Kor once again in "Once More Unto the Breach" from the final season of Deep Space Nine. Instead of a nemesis, he was now a noble warrior — and a legend, if a slightly faded one. Kor was now a "Dahar Master," one of the highest ranks in the Klingon Empire, but it had been a long time since he'd tasted the sweetness of victory in battle. So Chancellor Martok had marginalized him. That is, until Kor took it upon himself to pilot a Bird of Prey into battle against multiple Jem Ha'dar warships during the Dominion war, and did so flying alone. He gave his comrades — and Chancellor Martok — the chance to escape certain death, while sacrificing himself. A worthy end to a foe turned friend.
8. A Klingon Wedding! — "You Are Cordially Invited"
Let's end on a lighter note, because one thing to take away is that the Klingons really like to party. Worf's wedding to Jadzia Dax on Deep Space Nine is a spectacularly debauched affair and shows that while the Klingons may love a good fight, they love drinking, wenching, and singing (especially old warrior ballads) just as much. At times they can be like the rowdiest fratboys in the galaxy. Just don't let them pull a Bat'leth on you.