The Defiance was a cruiser used in patrol service before the outbreak of the Clone Wars. Commanded by Pell Baylo, the ship saw many battles against pirates. By the time of the Clone Wars, the ship had been converted into the Defiance Flight Training Institute, also known as "The Baylo School."
Cadet Sloane and Darth Vader aboard the Defiance
Five years after the formation of the Galactic Empire, Emperor Sheev Palpatine and Darth Vader visited the Defiance where the Emperor was having a meeting with several Imperial Navy chiefs to discuss the future of the Imperial Naval Academy. During a routine training mission, Baylo programmed a hyperspace route which would crash the Defiance into Christophsis's sun. Baylo was a Republican loyalist who had become upset with the creation of the Galactic Empire, which he considered to be a hostile force. Baylo's treachery was uncovered by cadet Rae Sloane and Vader, and Baylo was Force choked to death by Vader. The Emperor, was upset that Vader had taken matters into his own hands, and ordered the cruiser to be renamed the Obedience, both as a final insult to Baylo and as a signal to other naval officers who may be Republic loyalists as well as Vader himself.