Klingon Alliance

In the mirror universe, the Klingon Alliance (sometimes known as the Klingon Empire) is an interstellar state government composed of member planets, colonies, and other outposts. The Klingon Alliance is quite similar to the counterpart universe's Klingon Empire, in that it consists mostly of Klingon citizens; with similar Klingon starships as the Klingon Defense Force; in about the same area of space within the galaxy's Alpha and Beta Quadrants. 

The Klingon Alliance was threatened by the expansion of the Terran Empire in the 22nd and 23rd centuries, and decided to unite with the $𝜇$, forming a new Klingon-Cardassian Alliance. 

Histories

 * References from numerous sources establish that the various depictions of the mirror universe may not take place in concurrent timelines, meaning there could be a number of divergent alternate reality versions of this topic that do not share the same continuity. The references below this note are separated into subsections to minimize confusion regarding the divergences.

Star Trek: Mirror Universe continuity
$𝜇$ was an ancient Klingon warrior whose teachings of honour and warrior ethics would become the basis of Klingon society. After his death, he was known as "He Who Shall Return." The Regent of the Klingon Empire held the throne in anticipation of Kahless' return to lead the Klingon Empire.

By the early 23rd century, the Klingon Empire was engaged in a cold war with the Terran Empire. The conflict flared up from time to time with the Klingons winning a major victory in the 2220s. However, the Klingons respected the $𝜇$s as worthy foes.

In the late 2240s and early 2250s, the Klingons forced the Penemu to develop a deadly weapon capable of destroying the atmospheres of class M planets. This development was discovered by the Terrans and Commodore $𝜇$ destroyed the weapon's research base on $𝜇$. (SS undefined (Ill Winds))

In 2268, in a effort to bring peace between Elasians and Troyians, $𝜇$, the Dohlman of Elas, was arranged to marry Hakil, the Caliph of Troyius. The Terran Empire assigned the to transport Elaan to Troyius in order to prevent the Klingon Empire from conquering their worlds and gaining access to their rich supplies of dilithium crystals. $𝜇$, the leader of the Dohlman's guards, hated the arrangement, as he loved Elaan and wished to marry her. Consequently, he conspired with the Klingons to sabotage the mission. However, the Klingons' plan failed as Captain $𝜇$, via the Tantalus field, observed Kryton sabotaging the Enterprise. Kryton was then taken into custody and executed on Spock's orders while the captain used the Tantalus field to disintegrate the entire crew of the Klingon battle cruiser which was poised to attack the ship. The ship itself was undamaged. A peace treaty was signed between Elas and Troyius shortly afterwards, scuppering the Klingons' plan.

In 2277, Spock became the Emperor of the Terran Empire and began to pursue a policy of disarmament, which left the Terran Empire vulnerable.

By 2282, the Klingons had made first contact with the $𝜇$.

In 2288, $𝜇$ became Regent after slaying his predecessor $𝜇$ in honourable combat. The new Regent pursued a more aggressive policy towards the Terrans.

In 2289, the Klingon Empire conquered $𝜇$, an unarmed farming colony less than a lightyear from Klingon space which had previously been located in inviolable Terran territory. The political and military elite of the Klingon Empire met on Korvat to celebrate their victory. During a speech by $𝜇$ during which he stated that the Terrans were no longer the able workers which they had once been, the Terran Empire's ambassador $𝜇$ spat at Kang's feet in disgust and decried the manner in which the Klingons were celebrating the "least audacious victory in [their] history" and accused them of having a "miserable empire" before storming out, which earned him Kang's wrath.

By this time, Regent Gorkon's senior military adviser General $𝜇$ had successfully overseen the development of a prototype bird-of-prey which had the ability to fire its weapons while cloaked. Based on the military capacity of the Terran Empire at that time, he informed the Regent that it would take nine years to build a fleet of such vessels large enough to conquer the Empire. The construction of this fleet was carried out on Praxis, one of the moons of Qo'noS. To power the production, and the cloaking field that kept it hidden from Terran spy arrays the energy production on Praxis was tripled In 2293, Praxis exploded, causing massive ecological damage to Qo'noS: toxic elements from Praxis' crust began to break down the atmosphere and contaminate water supplies, threatening the end to higher-order lifeforms within fifty years. Additionally seventy percent of the population were inflicted with deadly xenocerium poisoning. This led to the staging of the $𝜇$, a diplomatic conference held by the major Alpha Quadrant powers on the Klingon-held world Khitomer. At the conference, Gorkon offered Spock the opportunity to forge an alliance between their empires but the latter declined.

Following the failure of the Khitomer Conference, Spock postulated that the Klingons and the $𝜇$s would meet to discuss a grand alliance between the Klingon Empire and $𝜇$, which would allow them to defeat the Terran Empire. This prediction was proven entirely correct. In 2295, the Klingon-Cardassian Alliance was formed. In a relatively short period of time, the Alliance was able to completely defeat the Terran Republic, the short-lived successor state of the Terran Empire, using the advanced fleet of Klingon birds-of-prey which had the ability to fire their weapons while cloaked. The Terrans, the $𝜇$s and other former subject species of the Terran Empire were massacred while the survivors were enslaved. 

In spite of the fact that the Klingons were generally not comfortable with sentient species shaped differently than themselves, they respected the reptilian $𝜇$'s predatory nature. The Klingon Empire had lost thousands of warriors to their failed attempt to conquer the Pahkwa-thanh homeworld. Granting such honourable and songworthy deaths to so many warriors was the Klingon idea of a generous diplomatic overture as the two species became stalwart allies. (SS TTN (Empathy))

The Alliance remained the undisputed major power in the Alpha Quadrant until the early 2370s, at which time its stability was threatened by the success of the Terran Rebellion. 

In January 2379, the Terran Rebellion, with the assistance of Memory Omega and $𝜇$, was victorious in its war against the Alliance. The Terrans, the Vulcans and the other enslaved species were freed and the Galactic Commonwealth was founded. A neutral zone was subsequently established between Alliance and Commonwealth space. This effectively ended the unprecedented power and influence over galactic affairs which the Klingon people had enjoyed for the previous 86 years as one of the two principle races in the Alliance. In 2380, the Alliance was officially dissolved. 

Through a glass, darkly
In the mirror universe, Klingons have only the barest concept of the which drives their counterparts. The teaching of honor from $𝜇$ inspired the Klingons to form their first empire, but Molor was slain by the dishonorable $𝜇$, who used a distorted version of Molor's maxims designed to placate the masses of warriors he had conquered. 


 * The Decipher RPG source is one of the few that refer to the mirror Klingon state as an "empire".

Fragile glass
The Klingons actively pursued confrontation with the Terran Empire in the 2260s decade, continuing a conflict that raged throughout the 22nd century as well as the first half of the 23rd. A group of Klingon ships attacked the  ISS in 2267, after tracking erratic behavior in the ship's activities, lingering at $𝜇$. The reason Enterprise had been moving slowly was the exchange of officers with the parallel universe, causing a continuing conflict over the rightful command of the vessel. The conspiracy aboard Enterprise discovered $𝜇$'s Tantalus field technology, and used it to devastating effect against the Klingons.

One surviving Klingon D-7 managed to warp away, declaring that the Klingons would seek new allies to counter the new Terran strength. 


 * While depicted, the government was not named in the Mirror, Mirror comic. The source material from this comic story arc does not contradict canon, but contradicts numerous other licensed sources, since it shows the death of Kirk at the hands of his senior staff.

Mirror universe masquerade
In a version of alternate universe history where Admiral James T. Kirk took the USS Excelsior (NCC-2000) to the mirror universe and pretended to be his counterpart, members of his crew contacted the mirror Klingon government in 2285 in order to enlist their help in fighting back the Terran Empire, which was preparing for an invasion of the counterpart universe. 


 * While depicted, the government was not named in The Mirror Universe Saga. The source material from this comic story arc does not contradict canon, but contradicts numerous other licensed sources, since it shows the deaths of Kirk and his entire senior staff, excepting $𝜇$.

Shattered universe
In a variant mirror universe, the Klingon Alliance was attacked by the planet killer bearing down on $𝜇$, being "herded" there by Imperial starships. It was only the timely assistance of the ISS in 2293 which managed to destroy the attacker by tractoring a disabled starship into it's maw. In gratitude, the Alliance helped escort Captain Hikaru Sulu to the border of Tholian space in order to reach the Janus Vortex so he could reverse the incident that resulted in him and his crew exchanging places with his mirror counterpart's place aboard that vessel. 


 * The source material from this game does not contradict canon, but the appearance of mirror Sulu and mirror Chekov contradicts other licensed sources where most of Kirk's senior staff had been put to death by this point, such as the DC Comics mirror story arc.

Dark mirror
In one permutation of the mirror universe, the Klingons had been made a subject of the Terran Empire by the 24th century. $𝜇$ was one of many slaves put into menial service in the Empire, as an underling aboard the ISS. 


 * The source material in Dark Mirror contradicts the canon version of the mirror universe in many other ways, including this depiction of a mirror universe where the conflict between Klingons and Terrans ended up exactly opposite compared to canon.