Brought to compliance in the 135th year of the Great Crusade. Known for its stable warp routs, Dark Age knowledge repositories and deep fuel reserves. It has known human habitation for well over 10000 years. With the civil war forcing commanding the attentions of the human forces, Xenos of the periphery are making ventures further core ward than they have for hundreds of years. There is also a rumor of an Ork Hulk in the far reaches of the system.
The volatile inner system is contained by a dense asteroid field in remarkably stable orbits. These asteroids are high in lead and iron and so block much of the outpouring radiation. The adepts of the Mechanicum declare that they were moved to their current position in the Dark Age, most likely as a terraforming measure to ensure the rest of Alkoss was not raked by the power of it's fluctuating sun.