Worf may have been the only Klingon in Starfleet in Star Trek: The Next Generation, but his presence on the USS Enterprise-D proved how far things had come between the Federation and the Klingons. Having been raised by humans, Worf felt disconnected from his Klingon roots, but he nevertheless embraced Klingon culture. TNG offered more insight into the Klingons and their way of life, revealing more about their culture than TOS ever had. Yet when the Klingons were first introduced, Star Trek planted the seeds that they would one day become allies with the Federation, setting up every Klingon story that followed.
Star Trek: TOS Predicted Worf & Peace With Klingons 20 Years Before TNG
The Klingons First Appeared in Star Trek: The Original Series Season 1, Episode 26, "Errand of Mercy."
The Klingons made their debut in Star Trek: The Original Series' "Errand of Mercy," which sees Captain Kirk and the USS Enterprise visit the planet Organia. Kirk and Spock (Leonard Nimoy) soon find themselves trapped on the planet, facing off against Commander Kor (John Colicos) and his men. Eventually, the Organians intervene, revealing themselves to be incredibly powerful incorporeal beings who then take control of both the Federation and the Klingon forces. After the two sides agree to cease hostilities, the Organian leader says: "It is true that in the future, you and the Klingons will become fast friends. You will work together."
Although Kor is quick to protest this idea, the Klingon Empire will eventually ally itself with the Federation. By the time of Star Trek: The Next Generation, the Klingon-Federation alliance is in full swing, and Worf becomes the first of his species to join Starfleet. Worf's presence on the USS Enterprise-D allowed TNG to explore Klingon politics and culture more thoroughly, influencing every Klingon story that came after. Klingons helped Captain Jean-Luc Picard (Patrick Stewart) and the Enterprise-D on several occasions, although some Klingons remained weary of the Federation alliance.
Star Trek VI: The Undiscovered Country Told The Story TOS Predicted
Captain Kirk & His Crew Fought To Preserve The Peace Talks
Star Trek: The Original Series' "Errand of Mercy" aired in 1967, twenty years before Star Trek: The Next Generation premiered, setting up one of the Federation's most important alliances. In 1991, Star Trek: The Undiscovered Country told the full story of how the Federation made peace with their long-time Klingon enemies. Worf had already been introduced in 1987 when TNG began, and The Undiscovered Country went back and explained the events that made it possible for a Klingon to serve in Starfleet: After the Klingon moon Praxis was destroyed, the Klingon Empire fell into turmoil and began pursuing peace with the Federation.
Because Klingons had killed Captain Kirk's son David Marcus (Merritt Butrick), Kirk had his own reasons for hating the Klingons, but he put aside his personal feelings for the betterment of the Federation.
As a cabal of Federation, Klingon, and Romulan officers tried to sabotage the peace talks, Captain Kirk and the Enterprise crew raced to prevent an attack on the conference. In the end, both the Federation and the Klingon Empire signed the Khitomer Accords, laying the foundation for lasting peace. For years after this historic alliance, the Romulans would continue working to sabotage the peace and reignite hostilities between the Federation and the Klingons. When Star Trek: The Original Series first introduced the Klingons in "Errand of Mercy," the creators had no way of knowing how influential that episode's storyline would become.
