Star Trek: The Original Series Timeline Explained

The timeline of "Star Trek" is a long and complicated one. It's been more than half a century since the first episode aired, and that was merely the first of ten TV series and counting, not to mention ten movies in the original continuity and three in a rebooted timeline. Within the "Star Trek" universe, the timeline is far longer than that, stretching from our own time (or long before if we start getting into ancient Vulcan history) to the 32nd century, where the later seasons of "Star Trek: Discovery" are set.

So for this recap, we'll limit ourselves to the in-universe timeline first "Star Trek" series that began airing in 1966, which most people now refer to by the retronym "Star Trek: The Original Series." What circumstances led to the events of that series, what were the major incidents during it, and what became of its ship and characters after it ended? Let's take a journey through it, piece by piece and year by year.

Long, long ago

The path that leads to Star Trek begins in 2063, when the eccentric scientist known as Zefram Cochrane creates Earth's first warp drive and proves that faster-than-light travel is possible. This is a major turning point for the human race, which was rebuilding from a long and bloody World War 3. There is still a long way to go, but Cochrane's invention marks a shift that leads to humanity not just getting back on its feet on Earth, but stepping out into the larger galaxy.

A nearby Vulcan ship detects the warp signature from Cochrane's test flight. The Vulcans figure that if Earth's people are now capable of traveling faster than light, it is time for them to meet people from other worlds. So the Vulcans land on Earth and introduce themselves to Cochrane and his contemporaries.

In time, Earth builds a variety of spacefaring ships utilizing Cochrane's warp technology, which comes in handy a century later when Earth and Vulcan join two other worlds, Tellar Prime and Andoria, in forming the United Federation of Planets. As interstellar diplomatic relations prove largely successful, the Federation expands to include more than 150 planets. Starfleet, which had already been formed on Earth to explore space and make contact with new worlds, is folded into the Federation upon its creation in 2161.

Not so long ago

The Constitution-class Starfleet ship commissioned as the USS Enterprise, bearing the registry number NCC-1701, is first launched in the mid-23rd Century, almost a hundred years after the formation of the Federation. Its first Captain is Robert April. From the very beginning, the Enterprise's primary mission is to explore the Galactic Frontier, seeking out previously undiscovered worlds and making contact where appropriate.

When April is promoted to commodore and steps down from command of the USS Enterprise, First Officer Christopher Pike is promoted to replace him. As captain of the Enterprise, Pike becomes one of the most decorated officers in Starfleet. During this time, Spock joins the crew as a science officer. This Enterprise crew visits the planet Talos, where Pike is briefly held captive by the highly evolved psychic beings who dwell there and has a brief romance with a woman named Vina (depicted in the original "Star Trek" pilot, "The Cage").

Later, Pike and the Enterprise come to the aid of the USS Discovery, whose crew includes Spock's adopted human sister, Michael Burnham (revealed in "Star Trek: Discovery" Season 2). The Enterprise plays a role in helping the Discovery and its crew travel to the far future (in the "Discovery" Season 2 finale, "Such Sweet Sorrow").

The five year mission begins

In 2265, Christopher Pike is promoted and Captain James T. Kirk is given command of the USS Enterprise. Commander Spock remains a science officer but also became Kirk's first officer. Chief engineer and second officer is Lt. Commander Montgomery Scott, affectionately known as Scotty. One of Kirk's oldest friends, Lieutenant Commander Gary Mitchell, initially serves as helmsman at Kirk's request. 

One of this crew's first missions sends them to the edge of the Milky Way Galaxy, where an encounter with a mysterious energy barrier imbues Mitchell with godlike psychic powers. Elizabeth Dehner, a doctor serving under Enterprise Chief Medical Officer Mark Piper, is also affected and later developed similar powers. Mitchell is driven insane by the experience and becomes a threat to the Enterprise and even the galaxy. Doctor Dehner sacrifices her life to stop him, and both perish. Captain Kirk keeps the circumstances of their deaths private, wanting Mitchell to be remembered positively. This all happens in the second "Star Trek" pilot, "Where No Man Has Gone Before."

Following this incident, Lt. Hikaru Sulu, who has been working in the science divison, becomes helmsman of the Enterprise. With Dehner's death and Piper's retirement, Doctor Leonard "Bones" McCoy became the chief medical officer. Around the same time, Lt. Nyota Uhura joins the bridge crew as a communications officer. With this crew in place, the Enterprise sets out on the five-year exploratory mission that is the focus of "Star Trek: The Original Series."

Year one

Although the time period is vague on the show, the original "Star Trek" is set three hundred years after it originally aired, so the first year of their mission, as depicted in Season 1, runs from 2266 to 2267. During that year, the USS Enterprise has a run-in with the Romulans ("Balance of Terror"), who haven't been seen since their war with Earth a century earlier. They also deal with the fall-out of failed negotiations with the Klingons ("Errand of Mercy"). Captain Kirk fights a Gorn captain ("Arena") and deals with the death of his brother, Sam Kirk ("Operation — Annihilate!"). The Enterprise crew also has their first encounter with the notorious con artist and pimp Harry Mudd ("Mudd's Women").

Admiral Christopher Pike briefly returns to the Enterprise after an accident leaves him paralyzed and nonverbal. After a fiercely loyal Spock helps Captain Kirk understand the situation, they take Pike to Talos, where the Talosians can help him live out his life free of physical constraints, and where he is reunited with Vina ("The Menagerie").

Perhaps most significantly, the USS Enterprise encounters a drifting derelict ship, the USS Botany Bay, which houses cryogenically frozen war criminals from the Eugenics Wars of the past. Their leader, Khan Noonien Singh, is revived and attempts to take control of the Enterprise. Kirk defeats Khan, leaving him and his allies marooned on the planet Ceti Alpha V. Starfleet historian Marla McGivers, who had fallen in love with Khan and betrayed the Enterprise for him, chose to join him in exile rather than stay on the ship and face court martial ("Space Seed").

Year two

As the mission entered its second year in 2267 (corresponding with the fall 1967 debut of Season 2), the bridge crew of the USS Enterprise is joined by Ensign Pavel Chekov, a young man from Russia. He and Sulu become close friends, and in time he becomes a vital member of the ship's inner circle.

The Enterprise soon travels to Spock's home planet of Vulcan for his marriage to his betrothed, T'Pring. However, T'Pring had already chosen another lover in Spock's absence, and the visit became a fiasco in which Spock and Kirk are made to engage in ritual battle until Kirk fakes his own death. Freed from his betrothal, Spock returns to the ship a confirmed bachelor ("Amok Time").

Later that year, the Enterprise crew is involved in an incident on Deep Space Station K-7 involving a poisoned shipment of grain, a Klingon spy, and the rapidly reproducing trilling fuzzballs known as tribbles, which are peddled by the shady Cyrano Jones ("The Trouble with Tribbles"). Although they didn't know it, they are also visited at this time by time travelers from the 24th Century, who infiltrate the Enterprise crew to avert an attempt to change history by the future version of the same Klingon spy (as seen in the "Star Trek: Deep Space Nine" episode "Trials and Tribble-ations").

Other incidents in year two included the return of Harry Mudd ("I, Mudd"), the discovery of a Mirror Universe ("Mirror, Mirror"), and a visit from Spock's parents ("Journey to Babel").

Year three

The third year of the mission (and the 1968 TV season) kicks off with a bizarre incident in which an alien civilization steals Spock's brain from his body. Even weirder, Spock survives the incident long enough for his brain to be returned to his skull before he suffers any permanent effects ("Spock's Brain"). Spock's brain was also affected by an encounter with a Medusan ambassador, a member of a non-humanoid race whose appearance drives any humanoid who sees one mad. Fortunately, Spock is also able to recover from this incident ("Is There in Truth No Beauty").

Another non-humanoid alien race, the Tholians, traps the Enterprise in an energy web for trespassing into their space. Spock is in command at the time and is unwilling to move the ship because Captain Kirk has shifted out of phase with the universe after an incident involving the USS Defiant, and they need to remain in the area to get him back safely ("The Tholian Web").

The Enterprise command crew also takes part in an undercover mission aboard a Romulan ship, where Kirk is able to steal a Romulan cloaking device while Spock romances a female captain ("The Enterprise Incident"). As the third year draws to a close, the crew has a series of increasingly bizarre adventures. These include an encounter with Abraham Lincoln ("The Savage Curtain"), finding themselves trapped in the past of a doomed planet ("All Our Yesterdays"), and Kirk temporarily swapping bodies with a nefarious woman ("The Turnabout Intruder").

The mission continues

Since "Star Trek: The Original Series" only ran for three seasons, it fell to other media to tell the stories of the last leg of the USS Enterprise's five-year mission. Countless comic books and novels have been published that recount other adventures of Captain Kirk and his crew. While they're not really considered part of the official canon of Star Trek continuity, they've still provided ample entertainment for fans nostalgic for the show, and some of the best ideas that originated in them have found their way into more widely-seen media.

In 1973, the USS Enterprise returned to TV screens on "Star Trek: The Animated Series." Whether this series counts as official canon has been the subject of much debate, but so much of it has been referenced in later TV and movies (including the second animated series in the franchise, "Star Trek: Lower Decks") that it seems safe to count. However, certain things, such as life support belts (a force field-based method of saving money by not redrawing the characters in space suits), have to be glossed over.

During the leg of the mission depicted on the animated series, Ensign Chekov is replaced by Lieutenant Arex, an orange alien with three arms and three legs. Lieutenant Uhura is sometimes replaced at the communications station by Lieutenant M'Ress, a catlike female alien.

On one memorable adventure, Spock goes back in time to his childhood on Vulcan ("Yesteryear"). Harry Mudd also returns to cause more trouble ("Mudd's Passion"), as do Cyrano Jones and his tribbles ("More Tribbles, More Troubles").

The crew reunited

Fans pick back up with the crew after the end of the five-year mission in the first of the "Star Trek" feature films, "Star Trek: The Motion Picture." Jim Kirk has been promoted to Admiral and becomes Chief of Starfleet Operations, which is based at Starfleet Headquarters in San Francisco. Spock returns to Vulcan and begins training to purge himself of emotions and further devote himself to logic. Doctor McCoy leaves Starfleet to practice medicine on Earth. Three years later, in 2273, the USS Enterprise is being completely refitted under the supervision of Scotty and the ship's new captain, Willard Decker. 

When a massive, destructive anomaly was discovered heading for Earth, Admiral Kirk assumes command of the Enterprise on a mission to intercept it, to the annoyance of Decker, who is temporarily demoted to first officer. At Kirk's request, McCoy's Starfleet commission is reactivated, bringing him back to the Enterprise as well. After the new science officer is killed in a transporter accident, Spock soon rejoins the crew as well.

After the anomaly is revealed to be an ancient probe from Earth, Captain Decker joins with it so that it can fulfill its purpose of reuniting with its creator. Decker and the anomaly vanish, leaving Kirk in sole command of the USS Enterprise.

The death of Spock

In 2285, the Enterprise is on what is meant to be a short training voyage, but that changes when Khan Noonien Singh reappears, looking for Admiral Kirk. The planet where Kirk left Khan and his people more than fifteen years earlier has become a harsh desert after a catastrophic shift in orbit, and Marla McGivers, who had become Khan's wife, was killed. Khan and his remaining followers escape by commandeering the USS Reliant, but Khan can't be satisfied until he takes personal revenge on Kirk. Kirk barely manages to defeat Khan, but the Enterprise sustains heavy damage. Captain Spock saves the rest of the crew by manually repairing the ship's main reactor but receives a lethal dose of radiation in the process. Spock reassures Kirk that he would always be his friend, and then dies ("Star Trek II: The Wrath of Khan").

During his funeral service, Spock's body is launched from the Enterprise and falls to the surface of a planet that is in the process of being radically terraformed by the experimental Genesis Device. This creates a unique opportunity to restore Spock to life. Before he died, Spock infused Dr. McCoy with his psychic essence, which is soon found to have a deleterious effect on the doctor's mental state, which can only be cured by returning it to the correct body. 

The return to Earth

To reunite Spock's psychic essence with his body that is regenerating on the Genesis Planet, Kirk and his loyal crew (McCoy, Scotty, Uhura, Sulu, and Chekov) must defy Starfleet orders and steal the USS Enterprise from spacedock. In the course of rescuing Spock, the Enterprise has a deadly encounter with Klingons that results in the destruction of the Enterprise ("Star Trek III: The Search for Spock"). Escaping in a commandeered Klingon Bird of Prey, the crew travels to Vulcan, where Spock can heal. They stay there for three months, until early 2286.

As the crew travels back toward Earth on the Bird of Prey, facing court-martial for their actions, a mysterious alien probe is discovered heading toward Earth, leaving a path of destruction in its wake. When Spock realizes that the probe is attempting to contact humpback whales, an extinct species in the 23rd Century, the crew traveled back in time to 1986 and returns with a mated pair of whales, saving Earth from the probe. With their heroism taken into account, the charges are dropped at their court-martial. However, Kirk is demoted back to Captain for disobeying Starfleet orders and given command of the newly commissioned Enterprise NCC-1701-A ("Star Trek IV: The Voyage Home").

The later years

In 2287, the new Enterprise and its crew are sent to deal with a diplomatic crisis when Federation, Klingon, and Romulan ambassadors on Nimbus III are taken hostage by a renegade Vulcan. The Vulcan, Sybok, is Spock's half-brother, who rejected Vulcan logic in favor of emotion and was exiled. He recruits a cult-like army by using his psychic abilities to help people conquer painful memories, inspiring gratitude and loyalty. Sybok, along with his followers, hijacks the Enterprise and travels to a mysterious planetoid in the center of the galaxy, where he believes he will find God. Kirk, Spock, and McCoy join Sybok on the planetoid, where they meet an entity claiming to be God, which turns out to be an incredibly powerful malevolent being who has been imprisoned there. Sybok is killed, and the entity is destroyed ("Star Trek V: The Final Frontier").

In 2293, three months before the aging Enterprise crew is scheduled to stand down, they embark on a diplomatic mission to accompany the Klingon chancellor to Earth for peace negotiations. En route, the chancellor is assassinated, while Kirk and McCoy are framed for his death. After being tried by the Klingons, they are sentenced to a prison planet, leaving Spock to root out a conspiracy to escalate hostilities between the two civilizations. Ultimately, peace is established, Kirk and McCoy are freed, and the Enterprise crew is free to move on to the next phase of their lives ("Star Trek VI: The Undiscovered Country").

A series of epilogues

Later in 2293, Kirk, Chekov, and Scotty are present as guests on the maiden voyage of the new Enterprise NCC-1701-B, where an incident involving a time nexus leads to James Kirk's disappearance. In 2371 he is discovered alive inside the nexus by Jean-Luc Picard, captain of the Enterprise NCC 1701-D, but Kirk dies helping Picard thwart the villainous Soran ("Star Trek Generations").

After retiring from Starfleet, Spock becomes an ambassador. He is instrumental in achieving peace with the Romulans. He also encounters Captain Picard and his crew during a crucial part of that effort (in the "Star Trek: The Next Generation" two-parter "Unification"). At the end of his life, Ambassador Spock travels back in time, finding himself in an alternate timeline alongside a younger version of himself and his friends, who led very different lives ("Star Trek" 2009).

Doctor Leonard McCoy, who has always been grumpy about being in Starfleet, ironically has the longest Starfleet career of the three. He becomes a branch admiral and Chief of Starfleet Medical. In 2371, as a very old man, Admiral McCoy tours the Enterprise-D during its first mission (in the "Star Trek: The Next Generation" premiere "Encounter at Farpoint").

In 2294, newly retired Captain Montgomery Scott is a passenger aboard the USS Jenolan when the ship crashes into a Dyson Sphere. Scotty manages to put himself into suspended animation using the Jenolan's transporter and is revived in 2369 by the crew of the Enterprise-D. After some time aboard the new Enterprise, he sets out aboard a shuttlecraft to enjoy his retirement ("Star Trek: The Next Generation" episode "Relics").

Hikaru Sulu becomes captain of the USS Excelsior and has his own illustrious career. Serving under him is a young Vulcan named Tuvok, who later becomes the chief tactical officer of the USS Voyager under Captain Kathryn Janeway (Tuvok remembers this time in the "Star Trek: Voyager" episode "Flashback").

Less is known about the post-Enterprise-A careers of Pavel Chekov and Nyota Uhura. Still, even if they retired to live quiet lives, they must have been remembered as Federation heroes for their many adventures serving under Captain Kirk. Even all these years, there are still many stories left to be told.