Klingons are one of the oldest and most popular Star Trek species. They appeared for the first time in the 1960s in Star Trek: The Original Series and continued to play an important part in the franchise. Even though their visage and character as well as their culture developed over time, Klingons were portrayed right from the start as a warlike race that had a proud spirit and didn't bow in front of anyone.
On the downside, they could also be overly aggressive to others. Their complex character and their common appearances in various Star Trek shows and movies brought them the love of many fans. But there are some important moments in Klingon history that everyone interested in the franchise should know about.
6 The Beginning Of The Klingon Empire, The 10th Century
Klingons traveled space prominently from the 22nd century onwards, but that doesn't mean the Klingon Empire is similarly old. It dates back centuries. The Klingon Empire was created in the 10th century when Kahless the Unforgettable fought and defeated the evil dictator Molor. To defeat Molor, Kahless used the first bat'leth ever, the iconic Klingon weapon. Kahless and his wife ruled the Klingons after Molor's death and created the First Empire.
What's more, Kahless came up with the code of honor that continued to characterize the Klingon society for centuries. Of course, not all of Kahless' accomplishments, such as his unification of all Klingons, survived. Klingons separated into various houses and by the time the 22nd century and the events of Star Trek: Discovery came, the Klingon Empire was no longer as unified as in Kahless' times.
5 Klingons Get The Warp Drive, After 1947
Just like the Vulcans and other Star Trek species, the Klingons had the ability to travel through stars sooner than the humans. The first human warp drive was invented by Zefram Cochrane and tested in 2063.
The Klingons, on the other hand, started using the warp drive sometime after 1947, possibly two centuries earlier than humans. The exact year when the Klingons had their first warp drive isn't known, but they have already achieved the warp six by 2152.
4 Klingons Make The First Contact With Humans, 2151
Captain Jonathan Archer was present for many great events, dangerous ones included. The first official contact between humans and Klingons falls into both categories. It happened in the first episode of Star Trek: Enterprise when the Klingon Klaang crashed on Earth and was shot by a human. Archer took Klaang back to the Klingon world Qo'noS and provided him with medical service, even though the Vulcans advised that they should let Klaang die with honor.
Overall, the first contact between the two species was a good example of their different approaches to honor and morality. Klaang was willing and expected to die while Archer and his crew fought to get him back to his home planet alive. As a whole, the first contact between Klingons and humans was much more peaceful than the first contact between the Vulcans and Klingons since the two species fought when they came across each other in the 21st century.
3 The Klingon-Federation War Starts, 2256
While Klingons and humans started on a more positive note than other species, by the mid-2250s, their mutual relationship was much worse. The Klingon Empire was divided into 24 houses, and they united only in their shared hate of the Federation. After T'Kuvma's death, the Klingons started fighting the Federation and killed thousands of people because they didn't like the Federation moving around in their space and potentially suppressing their culture.
The war finally ended victoriously for the Federation in 2257 when L'Rell, a more peaceful representative of the Klingons, took control over the planet. Subsequently, the Federation and the Klingons signed a peace accord and L'Rell went on to become the High Chancellor. Even though the war didn't last long, it was still devastating for the Federation as it cost them a lot of ships and lives.
2 The Brief War And The Treaty Of Organia, 2267
A decade after the Federation-Klingon war, another human-Klingon war erupted. This time, the war lasted only for a short time before the Organians, a powerful species, stopped it. The Organians were stronger than both the Klingons and the humans, and they opposed violence, so much so that they were able to destroy all weapons both of the species possessed.
Captain Kirk acknowledged that he had no other choice but to stop the conflict and even though they weren't happy about it, the Klingons chose the same option. The two species agreed to abide by the Treaty of Organia that set up a neutral zone, similar to the one existing between the Romulan and the Federation space.
1 The First Klingon Joins Starfleet, 2357
The enmity between the Klingons and the Federation continued even after the Treaty of Organia. That didn't stop the first Klingon ever, Worf, from joining Starfleet in 2357. Worf successfully graduated in 2361 and went on to serve on the starship Enterprise commanded by Captain Picard as well as on the Deep Space Nine space station under Captain Benjamin Sisko.
Worf was an excellent example that even a member of a potentially hostile species can thrive in the Federation and build a respectable career. Worf himself was proud of his accomplishments, despite the fact that a lot of Klingons didn't like the fact that he joined Starfleet and despised him for it.