Captain Preda was Commander of the Fifth Time Lord Battle Fleet in the Last Great Time War. She led a Battle TARDIS assault on the Dalek forces in the Tantalus Eye. Her fleet defeated the Daleks there, but shortly after she was killed when several Dalek stealth ships decloaked nearby and destroyed her fleet.
Later Rassilon said to the War Doctor and Cinder when they arrived on Gallifrey that he'd watched Preda's death with a heavy heart, but Cinder felt he wasn't truly concerned. (PROSE: Engines of War)