Andromeda Galaxy

From Hidden Frontier

The Andromeda Galaxy (M31, or NGC 224) is the closest spiral galaxy to the Milky Way Galaxy, located approximately 2,500,000 light years from the Alpha Quadrant at its closest point.

An ancient humanoid race from the Andromeda Galaxy became extinct following the destruction of their homeworld when their sun went supernova. Remnants of the species survived for a time on scattered outposts but eventually died out, leaving their android populations on their own. One of these android-populated outposts was the planet "Mudd" in the Milky Way Galaxy. (TOS 2.12 - "I, Mudd")

Centuries ago, Kelvans became aware of dangerously rising radiation levels in the Andromeda Galaxy, a development that was expected to make that galaxy uninhabitable for their species within 10,000 years. The then-Kelvan Empire dispatched expeditions of multi-generational starships to explore the neighboring galaxies for territories suitable for conquest and occupation. (TOS 2.21 - "By Any Other Name")

At some point, the Kelvans became engaged in a losing war with the Archein Empire, reducing them to the level of a resistance movement. The Archein are affected by the same "environmental" conditions as the Kelvans - it will render the quadrant of the Andromeda Galaxy that they occupy uninhabitable within ten years. This prompted the Archein to launch an invasion of the Romulan Star Empire through an artificial wormhole gate in an attempt to conquer planets that would subsequently serve as new colonies for their race. (ODY 1.01 - "Iliad")