Terran Empire

The Terran Empire is a state of the mirror universe, a parallel universe that exists on a different dimensional plane. Using force rather than diplomacy, the Terran Empire is the counterpart of the United Federation of Planets and a military dictatorship ruled by an Emperor.

In Star Trek Online, it is a non-player faction, using most of the same military assets as the Federation with cosmetic differences.

Culture
The Terran Empire was forged in several brutal wars. Treason and oppression are considered warranted means of advancement through the Empire's ranks. The Humans of the mirror universe (typically referred to as "Terrans") are openly nationalistic and fascistic, deeming themselves the born master race.

The First Terran Empire
Human literary works as far back as the 16th century show a divergence, except for Shakespeare. However no point of divergence from the Prime Universe has been established. The founding date of the Terran Empire is also unknown, but in 2155 it was said to have existed for "centuries" (suggesting at least the 20th century) and Roman-like allusions have been made by Terrans.

In 2063 Zefram Cochrane killed the first Vulcan to set foot on Earth with a shotgun. The Terrans looted the Vulcan ship and reverse-engineered its technology. The Terran flag is subsequently planted on Luna (by an astronaut in a 22nd century spacesuit) and Terran forces rapidly conquered Vulcan, Andoria, Tellar Prime, Denobula, and Gorlan by the 2150s.

In 2155 Rebels from oppressed worlds were on the verge of breaking the Empire's rule. The Empire was near total collapse until the managed to capture the U.S.S. Defiant (a Federation Constitution-class starship from the 23rd century), again infusing the oppressors with new advanced technology, giving them the advantage necessary to foster their dominance.

By 2256, the thriving Empire had rendered Qo'noS uninhabitable, but still faced opposition from rebel forces; an alliance of Klingons, Vulcans, Andorians and Tellarites who were opposed to the Empire. Many of these rebels were, however, wiped out by the Emperor's flagship. The Emperor however subsequently disappeared in a coup attempt, and the coup leader and his forces were killed when the Emperor's flagship were destroyed.

A transporter accident in 2267 resulted in an exchange of personnel between the Prime and Mirror universes - the Captains of the U.S.S. Enterprise and the travel to their counterpart's ships. Prime James T. Kirk was able to convince that the barbaric ways of the Empire need to change.

Spock subsequently rose to become Commander-in-Chief of the Empire and began to implement a policy of change (peace and disarmament). Unfortunately these reforms also weakened the Empire and made it vulnerable to conquest by the Klingon-Cardassian Alliance. The Empire fell, and Terrans and Vulcans became a slave caste of the Alliance.

Terran Rebellion
In 2372, inspired by their prime universe counterparts, a group of Terran rebels working on Terok Nor (DS9's mirror counterpart) manage to take the station from the Alliance. Using stolen plans for the, the rebels build the and succeed in pushing back Alliance forces.

Second Terran Empire
The Terran Resistance in the Bajor Sector eventually spread through the rest of the Alpha and Beta Quadrant, eventually forming a Second Terran Empire. By the 25th century this Empire reverted to its original aggressive nature, ruling oppressively over its territory and initiating a series of hostile incursions into the prime universe. The new emperor rose to power after a strange encounter gave him god-like powers.

In 2409, Terran forces begin providing aid to True Way forces and the Empire begins a major incursion in the Badlands. Around the same time, the Orb of Possibilities is returned to mirror Bajor, aiding the rise of Captain Leeta. The following year, Admiral Leeta defeats the Iconians 200,000 years in the past and takes challenges the Emperor's power using a combination of future technology from the Temporal Liberation Front and aid from the Pah-wraiths. 

In 2410, the was displaced from the 23rd century and led to Captain Killy seizing Pahvo. While her plans were thwarted, and the Discovery returned to the past, Killy remained at large.

Cardassian Struggle

 * : The player discovers that the True Way have used the stolen Orb of Possibilities to open a portal to the Mirror Universe, and have been negotiating an alliance with Captain Leeta of the Terran Empire.
 * : The player travels to the Mirror Universe, confronts Captain Leeta, and returns the Orb of Possibilities to Hathon on Bajor.

Ongoing Terran Incursion (Level 50+ PvE Missions and Battlezones)

 * : The Empire attacks Vauthil Station, sending dozens of warships led by a dreadnought.
 * "Tholian Incursion": An Odyssey-class Dreadnought Cruiser has been captured by the Tholian Assembly and is being held in a facility on Nukara Prime.
 * : The Crystalline Entity will occasionally generate numerous interphasic rifts, allowing Terran Empire vessels to enter the battle and hamper the players' attempt to destroy the Entity.
 * : Using the Orb of Possibilities, Leeta, now an Admiral, transports mirror-Terok Nor over to the prime universe.
 * : After boarding mirror-Terok Nor and defeating Leeta, she beams out and the player retrieves the Orb of Possibilities, thereby returning Terok Nor to its universe.
 * Badlands Battlezone: Admiral Leeta leads a full-scale invasion of the Prime Universe in the.

Future Proof

 * : Leeta and her Terran forces join the Temporal Liberation Front, claiming that the disappearance of U.S.S. Defiant wasn't an accident, but Envoy's gift to her Empire. Inside the Defiant's computer was a message just for her, promising her control over her own universe in exchange for assistance in the Temporal War. As a thank-you, Leeta shoots Daniels, killing him and restoring Envoy's physical appearance. Leeta briefly engages the player and other temporal agents in the orbit of New Khitomer, before regrouping with the rest of TLF forces and leaving for Procyon V.
 * : When her forces fail to keep the player from reaching the U.S.S. Enterprise and delivering the Tox Uthat, Leeta tries to defeat the player herself, but ultimately fails. Unsatisfied with the direction of the battle, Leeta orders her forces to retreat, leaving Noye and his forces behind to deal with their "foolish errand".

Mirror of Discovery

 * : Captain Sylvia Tilly and the is displaced to the prime universe in 2410 along with a hostile Klingon fleet. Tilly requests asylum from the Alliance.
 * : The player must counter Tilly's influence on Pahvo and return the Discovery to the 23rd century.
 * : Terran survivors of the attempt to subvert Pahvo once more.

Other

 * : Admiral Leeta's and her forces appear within a simulacrum recreation of the events of.

Missions formerly involved

 * : While the player retrieves the Orb of Possibilities, Terran forces support the True Way.
 * : Terran forces attack Deep Space 9.
 * : The player travels to the Mirror Universe and encounters Mirror and Klingon-Cardassian forces.

Military
The military arm of the Terran Empire is Imperial Starfleet, which mostly consists of Terrans. Ships in Imperial Starfleet are similar to their Prime Universe counterparts and may have been created from stolen plans. Unlike these however, most Imperial ships are capable of cloaking. Instead of the 22nd century vessels which were adorned with yellow markings, 25th century starships utilize red markings instead. Additionally, Imperial ships use an "ISS" prefix (Imperial Star Ship) instead of the prime Starfleet's "USS" (United Star Ship).

Starship classes

 * Terran Danube Runabout
 * Terran Peregrine Fighter
 * Terran Frigate
 * Terran Cruiser
 * Terran Escort
 * Terran Galaxy Class Cruiser
 * Terran Intrepid Class Science Vessel
 * Terran Nebula Class Science Vessel
 * Terran Rhode Island Science Vessel
 * Terran Science Vessel
 * Troop Transport
 * Terran Armitage Class Escort Carrier
 * Terran Command Cruiser
 * Terran Multi-Mission Explorer
 * Terran Prometheus Class Escort
 * Temporal Dreadnought
 * Terran Galaxy-X Dreadnought
 * Terran Odyssey Dreadnought
 * Terran Typhoon Class Battleship

Ground Forces

 * Terran Ensign Engineering Officer
 * Terran Ensign Medic
 * Terran Ensign Science Officer
 * Terran Ensign Tactical Officer
 * Terran Lieutenant Engineering
 * Terran Lieutenant Medic
 * Terran Lieutenant Science Officer
 * Terran Lieutenant Tactical Officer
 * Terran Combat Engineer
 * Terran Combat Medic
 * Terran Commander Security
 * Terran Commander Engineering Officer
 * Terran Commander Science Officer
 * Mirror Chief

Bosses

 * Admiral Leeta
 * Captain Killy
 * Evelyn Savea (mirror)
 * Coraline Fletcher (mirror)
 * Andrei (mirror)
 * Gerry Lifeson (mirror)
 * Desmond (mirror)
 * Orinoco (mirror)
 * Ian Kwon (mirror)
 * Lee (mirror)
 * Peart (mirror)

Member species
The Empire is known to constitute members of the following races:
 * Terrans (primary)
 * Andorians
 * Aenar
 * Bajorans
 * Benzites
 * Denobulans
 * Orions
 * Tellarites
 * Vulcans