Originally a member of a Dark Side Cult, Cronal went on to join the Imperial Intelligence community. He also served as one of the Emperor's personal agents, known as Hands. He was able to capture Luke Skywalker and Leia Organa shortly after their victory at Yavin, but of course they escaped. Vader's disappointment on top of Cronal's increasing madness due to his Sith stuff led to him taking off and disappearing from the Galaxy for a time.Once Palpatine and Vader were both dead after the Battle Of Endor, Cronal stepped back into action to assist Sate Pestage in leading the Imperial Remnant. Where he went after that is anyone's guess, but few care enough to speculate.