Dromund Kaas operation

The Dromund Kaas operation was a covert mission carried out by the Republic Navy and the Jedi Order in 3,641 BBY, during the Galactic War between the Galactic Republic and the Sith Empire, that saw the Republic Navy attack the Imperial capital planet of Dromund Kaas. The naval assault was but a diversion—while the Jedi Grand Master Satele Shan led the Republic Navy in engaging the Imperial, a small unit led by the Jedi Knight known as the infiltrated Dromund Kaas with the purpose of confronting the Sith Emperor. The Hero had foiled the Emperor's recent attempts to massacre thousands on the planets Belsavis,, and Corellia, a sacrifice that was necessary to start the Sith ruler's dark side ritual to consume all life in the galaxy, and the Jedi hoped to kill the Emperor before he could complete his plans.

The Hero and a small group of allies fought their way through the Imperial capital of Kaas City and stole the Sith Emperor's shuttle, which they flew to the nearby and battled their way through the Sith and Imperial Guardsmen who protected the Emperor. The Hero's allies engaged the Temple's defenders while the Knight and the astromech droid fought the Emperor in a final battle in the heart of the Temple. The Emperor was struck down in battle with the Knight, and though only the host body for the Emperor's immortal essence was slain, the Jedi and the galaxy at large believed him to be dead. The Sith Lord, long at odds with many of the Empire's policies, claimed the Emperor's space station and declared a New Empire, and the six powerful Sith known as the Dread Masters decided that they would claim the galaxy for themselves. The Empire and the Republic largely kept the Emperor's death a secret until the aftermath of the invasion of the planet a year later, when Republic Supreme Chancellor  publicly revealed the success of the classified operation.