In the mirror universe, Ferenginar was a vassal world of the Terran Empire and the homeworld of the Ferengi. It was destroyed by the Klingon-Cardassian Alliance in 2378 due to its support of the Terran Rebellion. (ST - Mirror Universe novel: Rise Like Lions)
Through A Glass, DarklyEdit
It was in 2250 when a Ferengi vessel was found to be "salvaging" communications equipment from an unmanned base that Imperial Starfleet became aware of their existence. The captain of the Ferengi vessel, Azark, used his charm and cunning and convinced the empire's captain to stand down his weapons. Azark further promised reparations and to lead the Starfleet captain and his favorite officers to the biggest "finders fee" in the galaxy. While en route to imperial headquarters, the crafty Azark easily won the life savings of the senior staff many times over, but had always given it back as a gesture of goodwill.
Upon being presented to the Emperor, Azark revealed his plan. Ferenginar would become a vassal world of the empire, and in return for its guaranteed submission, Azark would be made Grand Nagus. Emperor Stephane Louvin agreed to Azark's terms. Azark then staged a successful coup on Ferenginar with the help of Starfleet intelligence. In the aftermath, Starfleet personnel failed to notice the escape of the old Grand Nagus, nor did they notice the strong resemblance in portraits between Azark and the former Grand Nagus. To all appearance, it looked as through Azark had arranged to replace himself as Grand Nagus. Despite the evidence, the Ferengi always denied the rumors.
To end any further Imperial investigation, Azark funneled large amounts of ludugial gold into both the empire's coffers and those of Louvin. Over time, the empire and its elite became ever more dependent on the business savvy of the Ferengi and their world, much to the dismay of many security officials.
Ferenginar would have a small role to play in the fall of the empire. Following the damage caused to Earth by V'ger and the Cetacean Probe, Emperor Cray requested money from Grand Nagus Narl with Spock threatening to invade. Narl refused stating that the past money he and his predecessors had loaned the empire did not really exist, as it had not been backed by ludugial gold. Although Narl promised to keep the empire's financial troubles a secret, they were leaked in 2288 and resulted in corporations going bankrupt and trillions losing their jobs.
It is not clear to what extent the Klingon-Cardassian Alliance was involved with Ferenginar following the empire's demise. The planet had few resources and a dreary environment even by Alliance standards. (Decipher RPG module: Through a Glass, Darkly)
In this mirror universe continuity, Spock did not become emperor as he does in Glass Empires.
In retaliation over the T-9 energy converter that was stolen from the United Empire of Planets, the ISS Enterprise attacked Ferenginar in the 2360s, killing all life forms on the planet. This was followed by the terraforming and orbital re-alignment of Ferenginar so that it orbited the star Gamma Cephei. The planet was later resettled by a species approved by the Terran Empire. (TNG novel: Dark Mirror)