Second Yuuzhan Vong War

Prelude
During the depression that rocked the majority of the galaxy, the radical Yuuzahn Vong, Zing Krul, took the opportunity to assassinate the moderate senator, Lazzidh Drauzbith, and seize power in 266 ABY. With enough support from his people, Krul seceded from the Republic and formed the Yuuzhan Vong Empire.

Aftermath
With the deaths of their Supreme Overlord and Warmaster, the Yuuzhan Vong are forced to surrender and retreat to their homeworld of Zonama Sekot.

Unbeknownst to the Republic and Jedi, Darth Mulier had secretly been watching the battle and after the destruction of the Death Star recovered Lucius Cotte who had been unconscious since the explosion. The Sith would later brainwash Lucious into Sith service and modified his body.