Reynard's Free Station began its long and storied existence far from the Twelve Worlds, as a pre-Imperial human space colony in an asteroid belt. It served as a control, habitation and manufacturing center in which asteroidal resources could be processed into higher-value products for more economical interstellar shipment. After a life support catastrophe resulted in extensive population loss and evacuation, the station was abandoned for decades before being acquired by squatters, who after a few centuries grew to prosper, expanding the original station and building others like it.
After the conclusion of a major war resulted in a large number of surplus capital spaceships, a corrupt viceroy sold some of them to the squatters, who refitted some of their stations (still collectively called "Reynard's Free Station") with engines. They embarked upon a nomadic course, driven by population pressures and the increasing competition within the original asteroid belt. For several centuries, the motely assortment of "stations" plied connected space, harvesting mostly easily-available asteroidal resources in sparsely inhabited systems, occasionally moving from orbit to orbit with slow but efficient transfers. (The "stations", each individually small enough in cross section for wormhole passage, would rendezvous and be linked together after the trip through the wormhole.)
Although RFS had numerous conflicts with other galactic denizens over the years (e.g. over mining rights and wormhole usage - it could take several weeks for its thousands of modules to pass a wormhole gate), it had generally positive interactions with them until the Antimatter Wars. By that time, it had grown to include over 16 million inhabitants in 7,625 wormhole-passable modules, and would monopolize a wormhole gate for over a month to pass between systems, despite outstanding logistical coordination.
The Antimatter Wars, obviously, represented an existential threat to RFS, which proceeded far toward the pale of Imperial colonization as it could (it was already near the frontier, of course, due to its mode of operation). Unfortunately, economics in the time were not friendly to RFS, and, with Imperial forces distracted, its inhabitants turned rogue, blackmailing planets into providing them with additional propulsion components, propellant, etc by threatening them with a substantial quantity of bulk antimatter (which the station presumably had stolen from members of the Guardian sect earlier in the wars.)
In time, however, a remnant squadron of the collapsing Empire found RFS