Terran Empire
The Terran Empire was a repressive interstellar government dominated by the s from , locally named Terra by the 23rd century, in the mirror universe. The Empire ruled by terror, its  acting as its iron fist. In the Imperial Starfleet, officers often promoted themselves by killing superiors that did not follow the rules of the Empire. Torture was a common form of interrogation and discipline. (; )

Culture 

Going by rebellion sources, the culture of the Empire was fascistic, described as oppressive, racist and xenophobic, predicated on an unconditional hatred and rejection of anything and everything "other". Michael Burnham summarized this information by identifying the Empire as the antithesis of the United Federation of Planets in every way. ()

Humans of the prime universe could be violent, but violence was so ingrained in Terran culture that it self-propagated as an evolutionary survival mechanism, resulting in a strength that Michael Burnham described as "painted rust" – a facade hiding mutual fear between target and potential killer. From what she had heard of the Terran Empire, Katrina Cornwell came to the conclusion that, on the basis that prime universe Humans would be unaccustomed to the barbarism commonplace on Terran starships, the prime universe's Gabriel Lorca could not have survived his trip to the mirror universe. ()

 claimed that the only motivation Terrans had for any given action was revenge. ()

Religion 
During a debrief at Starfleet Headquarters in the 32nd century, the former Terran emperor, , revealed that an alternate First Contact Day was celebrated in the Terran Empire as a Holy Day, commemorating 's successful repulse of the first wave of a Vulcan invasion and the acquisition of Vulcan technology which was used to establish the Empire as a space-faring power. () She also claimed that an emperor's victims became their servants in the afterlife. ()

History

Early history 
In 2155, Commander  stated that the Empire had existed for "centuries". () One of the Empire's early outer space conquests was a landing on Terra's moon, Luna, where it planted its flag. ( opening credits)  Millennia ago, Terrans abandoned ideals such as freedom, equality and co-operation as they found them to be, in Georgiou's words, "destructive ideals that fuel rebellions". ()

21st century 
Humanity's first contact with an alien species in the mirror universe began exactly as it did in the traditional universe. Upon detecting 's warp signature, the Vulcan scout ship  landed in Bozeman, Montana, to make first contact with Humanity. Instead of welcoming the Vulcans in a spirit of friendship and understanding, the mirror Cochrane killed the first Vulcan to set foot on Terran soil with a shotgun, as the he and his fellow Terrans boarded and ransacked the Vulcan ship after killing the first officer also. According to mirror Archer, the Vulcan first contact was considered a prelude to invasion.

Instead of the Vulcans gradually releasing technology to Earth over time, the Terran Empire applied the stolen Vulcan technology to a policy of aggressive interstellar expansion. Because of this, the Empire was able to engage in technological research and development considerably earlier than its United Earth counterpart in the prime universe. ()

22nd century 
By the 2150s, the Terran Empire had already conquered the Vulcans, Denobulans, Andorians, Aenars, Orions, and Tellarites and had launched attacks against the Klingons, Rigelians, and Xindi. The flagship of the Empire, the , under the command of Captain Maximilian Forrest, had a much more racially-diverse crew than its prime-universe counterpart, with numerous Vulcans and Tellarites serving as crew members.

Due to the rapid initial expansion made possible by the captured Vulcan technology, the Empire's hold on its territories was initially weak. By 2155, some of the worlds conquered by the Terrans were beginning to rebel against Terran rule, leading to a long-running conflict, and after a disastrous defeat at Tau Ceti, the Empire came to the brink of collapse. Propaganda, however, conveyed the message that things were going in the Empire's favor and that the war would be over soon.

In that year, the , a Federation ship launched in the 23rd century of a parallel universe, was reported in Tholian space. The first officer of the ISS Enterprise, Commander Archer, reviewed this report and proposed a bold surgical strike at an asteroid base at which the Tholians were keeping the Defiant. Archer's proposal was quickly rejected by Forrest, causing Archer to mutiny against his captain and take control of Enterprise to retrieve the Defiant so its technology could be utilized against the rebellion. Enterprise traveled to the base and dispatched a boarding party to gain all information they could about the ship, and destroy it to prevent the Tholians from being able to use it. Unfortunately, during the retrieval operation, the Tholians attacked Enterprise and destroyed it, stranding the boarding party aboard the Defiant. ()

Following the destruction of the ISS Enterprise and the death of Captain Forrest, Commander Archer and his away team commandeered the USS Defiant. They proceeded to destroy the Tholian hangar in which the ship was being held and rescued a number of former Enterprise crewmembers, including , after apparent consideration of leaving their comrades stranded. Archer made a rendezvous with the , the flagship of Admiral . Archer vaporized the admiral and took command of both vessels.

However, this coincided with Commander  and Crewman  leading the other non-Human crewmembers on board the Avenger in a mutiny aboard the ship. They attacked the Defiant in hopes of destroying it but the mutiny itself was destroyed after Commander  reinitialized power systems that Phlox had attempted to disable. Commander Archer, acting as captain, then set a direct course for Terra, where he intended to declare himself Emperor of the Terran Empire. However, Hoshi Sato poisoned him with the assistance of his bodyguard, . The two then took control of the Defiant, and upon arriving at Terra, Sato declared herself Empress. ()

At some point between 2155 and the 2250s, the symbol of the Empire appears to have been altered. The earlier symbol closely resembled that of the United Earth government, depicting all of Terra's continents, though replacing a laurel of peace with an aggressive sword. However, by the mid-23rd century, the symbol, while remaining essentially the same, had a mirrored globe and what seemed to be an inverted delta in the background. (; )

23rd and 24th centuries 

By the mid-23rd century, the Terran Empire had conquered much of known space. However, it continued to be resisted by an alliance of non-Human species, including Vulcans, Andorians, and Klingons. Furthermore  of the  attempted a failed coup against Emperor . By 2256 or 2257 Starfleet engaged a rebel fleet at Porathia. () 

The same year, the Imperial Intelligence located the headquarters of the resistance on Harlak, which was destroyed by the . ()

In 2257, Lorca was able to resume his coup against Georgiou, having escaped the mirror universe and manipulated his way back with a Federation starship, the . For a while, the coup was successful, but Discovery had been informed that Lorca was Terran by the prime Michael Burnham, who Lorca had become obsessed with due to his relationship with , and Discovery defeated Lorca. However, although Lorca was killed, not only was Georgiou deposed, but the Charon had been destroyed, and she had been brought to the prime universe, resulting in a power vacuum. ()

Not long after this, the symbol was changed yet again, returning to its delta-less version and, this time, depicting only the continents of Terra's western hemisphere.

Eventually, the power vacuum was filled. The Empire encountered a Gorlan uprising, to which the , captained by , responded with the destruction of the rebels' home planet. Other feats of Captain Kirk by 2264 included the execution of five thousand colonists on Vega IX and the annihilation of all remaining inhabitants of Talos IV. In 2267, the Empire coveted the dilithium reserves of the Halkan homeworld and Kirk interceded to demand mining rights on behalf of the Empire.

In that year, crewmembers of the ISS Enterprise, including Captain Kirk, accidentally switched places with their prime universe counterparts of the , who in the same time were transported aboard the mirror version of the Enterprise. Kirk believed that the mirror  would one day become captain of the ISS Enterprise, and before returning to his own reality, he planted a seed of doubt about the inevitability of the Empire and whether violence was the only logical answer. Spock promised to consider Kirk's words, after realizing the Empire would only last about 240 years before being overthrown. ()

As Kirk predicted, the mirror Spock later became the captain of the ISS Enterprise and eventually rose to become Commander-in-Chief of the Empire. He began instituting major reforms that were very popular, turning the Empire into a more peaceful and less aggressive power. However, Spock's reforms left the Empire unprepared to defend itself against the emerging threat of a united Klingon-Cardassian Alliance, which managed to conquer the entire Terran Empire, turning the Terrans themselves into a slave race. The Bajorans, a people conquered by the Empire, came to be a powerful voice in this Alliance. ()

Subjugated races 
Andorians
Betazoids
Denobulans
Orions
Tellarites
Vulcans
Bajorans
Halkans
Gorlans
Kelpiens
Klingons

Appendices

Background information 
Robert Hewitt Wolfe decided to give the Terran Empire some formidable enemies. "Empires aren't usually brutal unless there's a reason. There are usually external or internal pressures that cause them to be that way," he commented. "So I just thought that if the parallel  was that brutal, there had to be a reason. And the reason was that the barbarians (the Klingons and the Cardassians) were at the gate." ()

Wolfe based the Terran Empire's predicament on historical precedents. He further elaborated, "My analogy was to the Roman Empire. The Roman Empire was as brutal and as nasty as it was because all around it, it had very aggressive barbarians that it was afraid of. The Chinese had the same thing, the Mongols were always there. So if you suddenly make the Romans nice guys, or the Chinese nice guys, well that's great and everything, but then the Mongols come across and it's all over. So that was kind of the idea." 

In the first draft script of , Benjamin Sisko described the Terran Empire as "corrupt, brutal, and doomed to collapse in any case." Mirror O'Brien, however, longed for the days when the Empire still existed and, later in the same script,  suggested reestablishing the Empire once the Terran Rebellion succeeded, with Sisko as the head of the Empire. Sisko himself, though, was against that idea, commenting, "The Terran Empire was every bit as corrupt as the Alliance." The Empire wasn't referenced at all in the final draft script of "Through the Looking Glass". (Star Trek: Deep Space Nine Companion - A Series Guide and Script Library; )

After the premiere of , screenwriter Jordon Nardino answered fan's questions through his Twitter feed. On the topic of the Terran Empire's relation to ancient Rome, Nardino stated that, "Lots of discussion in the room about the origins of the Terran Empire. In terms of canon, as always, it's what's on screen and nothing more. Unanswered questions leave avenues for future seasons / iterations of Trek to explore. I do not know if MU's "point of departure" is a specific incident, or the entire history of the MU somehow darkly mirrors ours. Canon locks us into an origin no later than the 20th century. Georgiou's "millenia" could be construed as hyperbole. But I firmly do not believe the Terrans are merely a continuation of the Roman Empire. MU earth history should roughly (but darkly) mirror our history as much as possible. I think Rome never falling would diverge too much. Leaders with imperial pretensions have adopted the styles and titles of the Romans since… well… the minute Rome "fell"! Napoleon took the title Augustus. So it's natural the Terrans looked back to Rome too." (After Trek' Gives Details On Georgiou's Meal, Mirror Stamets, Terran Empire History And More; )

On the topic of Terran history and the meaning behind 's elaborate title, Nardino stated:

"All Hail her most Imperial Majesty, Mother of the Fatherland, Overlord of Vulcan, Dominus of Kronos, Regina Andor, All Hail Philippa Georgiou Augustus Iaponius Centarius." But what's it mean??!?

When we began digging into the Terrans last year, I had just read a newer history of Rome and was excited to use it as inspiration. (SPQR by Mary Beard, check it out.) Here's some of the titles Roman Emperors used: 

So into her titles:

– Father of the Fatherland is easy, we turned that into Mother of the Fatherland (even tho we de-gendered Emperor, it felt right)

– Overlord of : an early conquest of the Terrans, they see themselves as their protectors. It's paternalistic / delusional.

– Dominus of Kronos: Terrans are very proud of conquering Qo'noS. Dominus is a harsher title the Emperor at the time took as a result (and Georgiou kept for herself). "We OWN them." Qo'noS mispronounced out of cultural chauvinism.

– Regina Andor: Andoria is a jewel in the Terran crowd. Subjugated warrior race. Early Terran conquest, pre-Sato. The title was created to celebrate this achievement. Now as for Georgiou's many names…

"Philippa Georgiou Augustus Iaponius Centarius" Philipa Georgiou: her given name and her family name, just like Prime. Augustus: the Terrans see themselves as inheritors of the Roman Empire so their Emperors take the title of its first Emperor. (After Trek' Gives Details On Georgiou's Meal, Mirror Stamets, Terran Empire History And More; )

Additionally, Nardino considered that Centaurius was the first system colonized by the Terrans owing to its proximity to Sol, thus resulting in the then-ruling Emperor taking its title in tribute. (After Trek' Gives Details On Georgiou's Meal, Mirror Stamets, Terran Empire History And More; )

Apocrypha 
In the game Star Trek: Voyager - Elite Force, part of the story involves going through a scavenger base composed of many species' ships. One of these ships is an Imperial Starfleet vessel, apparently dating back to the 23rd century. It is populated by Humans, who behave typically for the mirror universe. How it came to be in Voyagers canon dimension is unknown.

The novel The Sorrows of Empire depicts Spock becoming Emperor of the Terran Empire in 2277 and reforming the Empire into a democratic society, only to be overthrown and killed by the Klingon-Cardassian Alliance in 2295. At the same time, he engineers events leading to the formation of the Alliance, believing that their conquest of the former Empire will ultimately lead to their downfall and the establishment of a Federation-style republic in the future (which occurs in the follow-up novel Rise Like Lions).

In the   Dark Mirror – written and published before DS9's televised visits to the Mirror Universe – the Terran Empire (called the United Empire of Planets) is depicted as still existing in the 24th century, with Spock's reforms having been cut short by his death, speculated by Captain Jean-Luc Picard to be the result of his assassination after he pushed the Empire too far, too quickly. The crew of the mirror Enterprise-D are assigned a new mission to devise a means of bringing a ship from the prime universe into the mirror universe and then return after replacing its crew, the Empire having run out of territory that it can easily conquer in its own universe, but the Enterprise crew of the prime universe manage to sabotage their efforts and devise a method of detecting future incursions.

In the computer game Star Trek Online, by 2409, the Terran Rebellion has succeeded in overthrowing the Klingon-Cardassian Alliance and restored the Terran Empire to its former status as a major power in the quadrant. The Terran Empire of the 25th century has also returned to the old ways, having engaged in a series of hostile incursions into the prime universe. The Empire attempts to invade that universe using a trans-dimensional portal in the Badlands, and later allies with the Temporal Liberation Front. Imperial ships have markings similar to those used in the 22nd century, albeit red instead of yellow. The Emperor in the 25th century is revealed in the episode "The Eye of the Storm" (released in September 2022) to be the mirror counterpart of Wesley Crusher, who seeks to combine his powers from the Traveler with those of "the Other" (the mirror counterpart of V'ger) to become a god and destroy all of existence.

The mirror universe novella Saturn's Children identifies Andorians, Bolians, Tellarites, and Denobulans as part of the rebellion. Whereas the success of the Terran Rebellion has led to the reinstatement of the Terran Empire in Star Trek Online, in the novels, the democratic Commonwealth is established.

See also 
 Mirror universe people
 Mirror universe casualties
 Mirror universe history
 
 Terran Rebellion

External link 
 

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de:Terranisches Imperium
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ja:テラン帝国
mu:Terran Empire
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pl:Terran Empire
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sr:Теранско царство
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