The Final Battle (2381)
In 2381, the Borg discovered a subspace tunnel in the Delta Quadrant that led directly to the Azure Nebula. The Collective used this tunnel to send an invasion force into the Alpha and Beta Quadrants with the goal of eradicating humanity and any other races that stood between the Borg and total galactic domination.
Initial incursions were defended by the USS Excalibur and the Starfleet Corps of Engineers, these were minor skirmishes compared to what was to come. Anticipating a larger Borg invasion, Captain Picard asked that the Federation send as many ships as possible to the subspace terminus in the Azure Nebula. President Bacco negotiated for reinforcements from the Klingon Empire, Romulan Star Empire and Imperial Romulan State, Cardassian Union, Ferengi Alliance, the Tamarian Empire, and (through the Ferengi), Breen mercenary forces.
Before the allied forces could traverse the subspace passage and make their own assault, a force of over 7461 Borg Cubes attacked and destroyed the allied fleet that had assembled. Although the Federation was initially able to defend against the Borg attacks into Federation space using transphasic torpedoes, the Borg eventually adapted to the torpedo. However, the Federation starships USS Enterprise-E, USS Aventine and USS Titan, managed to convince the extremely powerful Caeliar to dissolve the Borg Collective and halt the invasion.
As a result of this, all of the former drones were absorbed into the Caeliar gestalt, the residual implants in Seven of Nine disappeared and the remnants of Locutus in Jean-Luc Picard were removed from his psyche. During the conflict, Borg Cubes decimated entire worlds, including Acamar III, Deneva, Qo'noS and Khitomer. The invasion attempt cost of 63 billion deaths and the fallout led to drastic changes in the political nature of the Alpha and Beta Quadrants, including an expansion of the Khitomer Accords and the formation of the Typhon Pact.
