The Iron Sun, a Pellaeon-class Star Destroyer, served the Imperial Navy before the Sith–Imperial War erupted.
Assigned to patrol the Deep Core in 127 ABY, the Iron Sun captured Celeste Morne, an ancient Jedi Knight and a "Shadow" connected to the Jedi Covenant from the era of the Mandalorian Wars. Morne, a Jedi who had self-exiled to contain the even older Sith Lord Karness Muur, utilized the Muur Talisman's power. This transformed the ship's complement into rakghouls, Sithspawn enslaved to her will through the Muur Talisman. For a decade, the abandoned and drifting ship remained in that state, until Cade Skywalker and the Mynock's crew "re-discovered" it in 137 ABY.
Morne orchestrated this event, using the Star Destroyer to forcibly extract the Mynock from hyperspace. Upon their arrival to investigate, Skywalker, accompanied by Shado Vao, Jariah Syn, Deliah Blue, and Imperial Knights Antares Draco, Ganner Krieg, and Azlyn Rae, faced Morne and her rakghouls, who separated them. From that point, the Jedi and Imperials planned the luring of Darth Krayt into a trap, intending to bring about the Sith Lord's demise.