Conclave at Katarr

The Conclave at Katarr was an event of the Old Sith Wars, occurring in 3952 BBY, and was the first major event of the First Jedi Purge that took place during that time period. That year, the last known hundred members of the Jedi Order secretly assembled on the planet Katarr, a colony of the Miraluka species, a race who saw through the Force. Jedi Master Atris summoned the Jedi she had kept contact with to a secret meeting on Katarr, seemingly to discuss the future of the Jedi Order. Her real intention, however, was to use the Jedi as bait, hoping their shadowy adversaries would reveal themselves. She leaked information about the conclave, which Sith Lord Darth Nihilus received.

Unfortunately for Katarr, Atris's plan backfired; the Jedi were not aware of the true extent of Nihilus' power. Nihilus arrived on Katarr before the meeting could begin and, using a unique variation of Force drain, he stripped the Force from Katarr's surface, killing every living being on the planet. Of all its living denizens, sentient, flora and fauna, Nihilus spared only one Miraluka woman, Visas Marr, who was subsequently recruited into the Sith as Nihilus's apprentice. 3,933 years later, the Jedi who survived Order 66 attempted to draw the Sith into a trap, with the similarly disastrous Conclave on Kessel.