The Amagons are a culture of space-faring criminals -- although they are most notable for being smugglers, they also engage in robbery, piracy, slave-trading and a myriad of other immoral schemes to turn a profit. They have even been known to engage in bounty hunting -- though without the approval of the R.A.C.
Jenna Stannis was, over the course of her own career as a smuggler, briefly associated with the Amagons. Some time later, Tarvin and a crew of Amagons answering to him boarded the Liberator after posing as a ship in distress -- a typical tactic of the Amagons to lure in unsuspecting victims.
Despite being an enemy of virtually every galactic government in the Milky Way's long history, the Amagons have been able to persist without interruption. This is largely credited to the fact that their base or bases of operation have never been discovered.
Source[]
The Amagons are derived from Blake's 7.