Silverstone is a silver rich planet in the Emeraldii sector, it's owned by a mercenary "government" called the "silverstone mercenaries"
History
Silverstone War
The Adairin Viserak Systems were fed up with the blatant piracy of the Silverstone forces, Arctus Sugof ordered Raark Spherianus and two other commanders to build their fleets and prepare for war , and on December 12th of 2478 the three fleets attacked Silverstone, the SCM was prepared for war, however, their forces were still no match for AVS.
Near the end of March of 2479 the Silverstone Government fell, it's leaders in hiding, the military was obliterated and most of their resources captured by AVS, the UTSEA condemned the attacks but were mostly uninterested in fighting a lengthy war with the Viserak .
The Silverstone people picked up the pieces in 2487 and joined a criminal underworld.
Aftermath
At some point the leadership fell to Mark Calrissio. The Axis of Freedom landed on Silverstone and fought a brief conflict with them before the mercenaries joined with them.