Andromeda Galaxy, or known as the Xurunia Galaxy, is a barred spiral galaxy approximately 2.5 million light-years (770 kiloparsecs) from Earth and the nearest major galaxy to the Milky Way. The virial mass of the Andromeda Galaxy is of the same order of magnitude as that of the Milky Way, at 1 trillion solar masses (2.0×1042 kilograms). The mass of either galaxy is difficult to estimate with any accuracy, but it was long thought that the Andromeda Galaxy is more massive than the Milky Way by a margin of some 25% to 50%.
Around 5980 BCE, a group of the Xurunian civilization known as the Carylonians went around the galaxy and caused a massive genocide against many civilizations and conquered the entire galaxy within weeks. First, they killed the Xurunian gouvernment and established the Carylonian Empire that controls the entire galaxy under a totalitarian regime. Andromeda Galaxy is under a no-entry zone within the local interstellar group, established by the Universal Galactic Alliance Federation.