Morcanth was a planet in the Unknown Regions, in a region disputed by three separate starfaring species for centuries, none of which accepted the concept of neutrality. Though in the Unknown Regions, the world did appear on some charts; however, only older charts held the correct name, as the planet had been renamed by the time of the Galactic Civil War.
Morcanth was the location of an underground base where a fallen Jedi Padawan, Winslau Da'k, imprisoned his own Jedi Master. Here Da'k used his powers to gain wealth and luxury, while delving into the dark side of the Force.
However, the Jedi was able to contact through the Force a group who were able to avoid capture by the alien fleets, infiltrate Morcanth, and defeat Winslau. The old master was released, later aiding his rescuers as a mentor and advisor.