The Ten Systems were ten star systems associated with the Earth Alliance. This included Heron's World on the edge of the ten systems, Kalsos, (AUDIO: The Death of Hope) and the planet Ridius IV in the seventh system, said to be "a hundred colonies" away from Earth. (AUDIO: The Seeds of War)
Galactic Heritage was able to track the Decayed Master to the Ten Systems, where he took over the Death-Match. (AUDIO: Death Match)
The Eminence War spanned across the Ten Systems. (AUDIO: Rule of the Eminence)