One of the planets under Imperial Control that does not recognize that fact is Pinco.  The Pinconians built up a fleet in exile after being conquered.  They participated in commerce raiding, but made no strategic move.  Then, near the end of Harloss' battles with the Terrans, they negotiated with Harloss, saying that in exchange for her assistance in liberating the planet, they would loan elements of their fleet to her. 

Then, as hostilities started to decay between the Terran Empire and the Arcturan Federation, they knew they had to stike before the war ended.  The initial assault, performed with only half of the available forces, retook the planet.  The Empire, not knowing the true strength of the Pinconian fleet, sent a less than adaquate force to retake the planet.  The Pinconians showed their true strength and beat them off. 

Additional Terran forces began to mass, and the Pinconians knew they could not hold the line without Harloss' support.  But Harloss was bound by a cease fire that was in place between the Terrans and Arcturans.  She sent a squadron as "observers," but they could not participate in the battle. 

The massed Starmada crushed the Pinconian fleet, although not without losses.  The Arcturan forces, perhaps in a moment of guilt, escorted the few surviving Pinconian ships out of the system.  Feeling betrayed, the Pinconian forces destroyed their "escorts" once out of the Imperial grip, and fled to Negali space.  They formed an Alliance with the Negali after assisting them in fighting a rouge Sssk Nesting, and the Negali gave them three colony planets.

The Pinconians claim that they will return to take their planet when the time comes, but as it stands they have less than thrity ships and cannot hope to be any strategic threat to the Empire for some time.  Will they eventually have their vengance?  No matter what, they vow to be a problem for the empire, and constantly attack Imperial freighters to show them that "this isn't over."