The Jedi Purge was a galaxy wide event of exterminating the entire Jedi Order from the galaxy, during the times between 298 BTC and 301 BTC. This purge was led by three Sith Lords, Darth Nihilus, Darth Traya, Darth Sion.
The Jedi Order disbanded and was hunted down by the Sith.
After the end of the Jedi Civil War the remaining Sith Lords took leadership of the remnants of Revan's Sith Empire. The Sith Lords each took a title for themselves. Darth Traya was soon betrayed by the other Sith Lords and was exiled from the Dark side. With Traya gone, Darth Sion left with his Sith Assassins to hunt for any Jedi. While Nihilus reformed his ship, The Ravager, from the graveyard of Malachor V and searched the galaxy for Jedi.
The Sith Lords were eventually defeated by Meetra Surik and her newly trained Jedi Knights. Surik and her companions then destroyed Malachor V and its graveyard of ships forever. After that Surik travelled to the Unknown Regions to find Revan, while her companions rebuild the Jedi Order.
The Sith Triumvirate
The three Dark Lords of the Sith that lead the remnants of the Sith Empire during the campaign became known as the Sith Triumvirate: