Terran Empire

The Terran Empire is the Human militaristic governmental authority controlling Earth and surrounding space through the use of the powerful Imperial Starfleet in the mirror universe. They were one of the dominant powers in the Alpha Quadrant in the 22nd and most of the 23rd centuries, until they were defeated by the Klingon-Cardassian Alliance around the turn of the 24th century. A Human-led uprising against the Alliance culminated in a restored Terran Empire by the turn of the 25th century.

History
As of the 22nd century, the Empire had existed for hundreds of years, and had begun its expansion into outer space in 2063, when a Vulcan starship detected the warp drive signature of Zefram Cochrane's warp ship. When the Vulcans landed, their leader was shot by Cochrane, the ship ransacked for its technology and its remaining crew tortured for technological information. By 2155, the Empire, armed with its newly acquired Vulcan technology, went on to conquer not only the Vulcans themselves, but the Andorians, Tellarites, Denobulans and Orions as well. The Empire also committed attacks on the Xindi and Klingons during its aggressive initial expansion.

This rapid expansion eventually proved to be detrimental to the young empire. With its martial resources spreading ever thinner, the Empire was in increasing danger of collapse due to a growing rebellion of its subjugated races. Contrary to Imperial propaganda at the time, the Empire had suffered a series of critical losses, including a major defeat at Tau Ceti, where the Imperial Starfleet lost twelve ships.

In 2155, the Empire's fortunes changed with the appearance of the counterpart universe's USS Defiant (NCC-1764) into their own universe. Commander Jonathan Archer, aboard the Terran flagship ISS Enterprise (NX-01), mutinied against Captain Maximilian Forrest and took the ship to the Vintaak system where the Defiant was being held by Tholians. Though Enterprise was destroyed in the process, Archer's team managed to wrest the vessel from the Tholians; who had lured it from not only another universe but over one hundred years into its future. Archer and the survivors of the Enterprise regrouped with the assault fleet but found only the ISS Avenger remaining, under heavy attack from a rebel fleet. Using the advanced Defiant weaponry, Archer defeated the rebels, and afterwards had the Avenger commander, Admiral Black, vaporized. Archer planned to use his two ships to become emperor himself. The aliens on board Avenger took control of the ship and attempted to destroy the Defiant, though they were unsuccessful and Avenger was destroyed. Archer was later murdered by Hoshi Sato who took the Defiant for herself and used it to destroy Starfleet Headquarters and take the Imperial throne (ENT episode "In a Mirror, Darkly")

Sato consolidated her power by marrying Thy'lek Shran of the Andorian Imperial Guard. She allowed her new husband to appoint Andorians to high-ranking positions in the Admiralty, intending to ensure the obedience of the remnants of Andoria's military forces. Sato had also intend to order the creation of a binary clone from General Shran's DNA and her own, hoping that a Terran-Andorian hybrid Emperor would further strengthen the ties of the two worlds.

However, Shran went on to betray Sato by luring the Defiant away from Earth, leaving it to be attacked by the Rebels and sending Sato into exile. As non-Terrans were forbidden to rise to the throne of Emperor, Shran appointed himself "Lord Protector of the Realm", de facto leader of the Empire; until he and now-exiled Empress' "heir" was of age to rule. Shran then planned to use the Empire's military might to destroy Andoria's rivals and promote his home world to rulers of the empire.

On route to her exile on Deneva Sato was captured by the Rebels who put her on trial for the crimes of the Empire. An impassioned speech to T'Pol by Sato convinced her to abandon the Rebellion and help her escape, in return the Vulcans would become equal partners with Terrans in the Empire. This, and the timely arrival of an Imperial assault fleet lead by the Defiant allowed Sato to regain her position and have Shran executed. Sato became the first of a dynasty which ruled until it was overthrown by Spock in the late 23rd century (ENT novel: Age of the Empress).

The Rise of Spock
By 2267 the Empire was the dominant force in the Alpha-Beta quadrant border region. A freak transporter accident transported an away team from our universe over to the ISS Enterprise (NCC-1701) while there "our" James Kirk convinced "that universe's" Spock that the Empire could not continue, and that the only logical solution was peace (TOS: "Mirror, Mirror"). Through this advice and a mind meld with our Dr. McCoy, Spock resolved to end the Empire.

In 2268, in an unprecedented move Coridan joined the Empire through diplomatic (as opposed to military) methods due to the influence of now Captain Spock, who had taken command of the Enterprise through the assassination of Kirk, and his father Ambassador Sarek of Vulcan.

Spock rose to Grand Admiral of Starfleet and later Emperor where he gave the peoples of the Empire greater freedoms, creating a common forum and Senate, disassembling Operation Vanguard as a threat to Galactic peace and ending Project Genesis before it entered its third phase in fear of it provoking the Klingons into an arms race. By early 2293, following the destruction of Praxis, the Terran Empire called for diplomatic talks at Khitomer, the Klingons, Romulans and Cardassians attended with the Tholians refusing the invitation due to lingering tensions over the Taurus Reach. At the talks, all major parties rejected overtures of peace made by the Empire while the Terrans rejected offers of military alliances from the Romulans and Klingons. This action infuriated the Klingon Regent $𝜇$ who swore to destroy the Terran Empire.

Fall of the Empire and its races
The same year Spock instituted reforms ending the Empire and transforming it into the Terran Republic, preaching disarmament and renouncing preemptive war as foreign policy. This was seen as a sign of weakness by the Empire's neighbors, and in 2295, the Klingons and Cardassians formed an alliance with the aid of a fleet of Birds of Prey (which could fire while cloaked) conquered the Republic: ending Terran rule and what remained of the Empire (TOS novel: The Sorrows of Empire).

Rebellion and Restoration
For the next several decades, human and associated races were enslaved by the Alliance. A Terran Rebellion rose first under Benjamin Sisko and then under Miles "Smiley" O'Brien.

25th century
By 2409, the rebellion had succeeded and a restored Terran Empire was once again a major power in the quadrant. (Star Trek Online)

Subjected Species

 * Alpha Centaurans (conquered and enslaved en masse in 2074)
 * Andorians (conquered some time between 2137 and 2155)
 * Denobulans (subjugated some time before 2155)
 * Orions (subjugated some time before 2155)
 * Tellarites (conquered some time after 2074)
 * Vulcans (subjugated some time between 2063 and 2074)
 * Bajorans (conquered in 2255)
 * Tiburonese (conquered in 2130)
 * Halkans (annihilated by the empire in 2267)
 * Gorlans (homeworld destroyed in 2263, but likely subjugated some time prior to 2155)
 * Betazoids (conquered in 2230)
 * Bolians (conquered in 2246)
 * Organians (subjugated in the mid 2260s)
 * Rigelians
 * Kaylar (conquered and enslaved in 2254)
 * Iotians
 * Ferengi (conquered in 2250)
 * Klingon (homeworld occupied in 2218)
 * $𝜇$s
 * $𝜇$s
 * $𝜇$s
 * $𝜇$s (annihilated by the empire in the 2260s)
 * $𝜇$s (conquered in 2155)
 * $𝜇$s (conquered in 2155)

Dark Mirror


The Terran Empire is commonly known as the United Empire of Planets. In this version of reality, Spock was assassinated in the late 23rd century before his reforms could be implemented. As a result, the Empire continued to exist into the 24th century and controlled all known space after conquering the Klingons and defeating the Romulans centuries before. 

Shatnerverse
In the "Shatnerverse", the Terran Empire came about from a Human-Vulcan alliance that became increasingly militant after discovering the role the Borg played in their first contact. By the late 23rd century, "Tiberius the First" ascended to the throne of the Empire however, was betrayed by Spock. Emperor Kirk's Prime Minister disarmed the Empire and preached peace. In response, Kirk brought the Klingons and Cardassians together into an alliance and helped them conquer the Terran Empire. (TOS novel: Spectre)

The Mirror Universe Saga
In The Mirror Universe Saga, the Terran Empire is a result of the defeat and subsequent occupation of Earth in the Earth-Romulan War. After ten years under Romulan rule, the Terrans rose up and vowed to conquer and never be slaves again. In this continuity, Spock decided against following the advice of the Kirk from our universe and instead remained first officer of the ISS Enterprise. In 2285 the Empire launched an invasion of the Federation by sending the crew of the ISS Enterprise to replace their versions in our universe (TOS comic collection: The Mirror Universe Saga).
 * The term "Terran Empire" was first used in the Enterprise episode "In a Mirror, Darkly, part 2", a prequel to TOS's "Mirror, Mirror". Mirror Universe (MU) Humans were referred to "Terrans" on DS9'', and a reference was made to "their Empire" in, but the actual phrase "Terran Empire" was first used by Hoshi Sato on "IaMD2".

Shattered Universe
In Shattered Universe, the USS Excelsior (NCC-2000) starts off on a mission to save the USS Enterprise (NCC-1701-A), under Commander Pavel A. Chekov, and the USS Ranger (Miranda class) trapped within the Janus Prime Vortex. While en route, the USS Excelsior fractures all of its dilithium crystals and loses power drifting into the vortex. The Excelsior is then transported to the alternate universe where it encounters the ISS and the. Commander Chekov destroys the ISS Ranger and then attacks the ISS. After the conclusion of the battle, the Janus Prime vortex is destroyed-as is the Excelsior's way home. Their only choice is to traverse the hostile alternate universe trough the Imperial Terran Empire where they encounter rogue Klingons, a starbase and the ISS, the M-5 computer, and finally an abandoned starbase along the Klingon border. While in the Klingon Empire, they encounter little resistance until they reach the Klingon homeworlds. There, they find the planet killer being escorted by a fleet of Terran starships. After saving the Klingon homeworlds, the Excelsior gained the trust of the Klingons. They then battled the $𝜇$ starship $𝜇$. The $𝜇$ is next. Inside the Romulan Neutral Zone, they found the hulks of several Terran warships. Once they passed those, they encountered the giant space amoeba and destroy it again; gaining the gratitude of the Romulans. Finally, through the Tholian Empire they then reach the Janus Ultima Vortex, having one final battle with the Terrans and ISS Excelsior to make it home.