Yuuzhan Vong

The Yuuzhan Vong were a warlike genocidal species that invaded the New Republic in 25 ABY in a conflict known as the Yuuzhan Vong war. Eventually defeated four years later, they were sentenced to self-exile in the Unknown Region.

Pre-War
Not much history exists regarding the Vong, however they had been in a conflict with the Chiss prior to the fall of the Old Republic, as the Chiss had warned the Galactic Republic, as well as the Galactic Empire, of a large threat that loomed just in the Unknown Regions. In 25 ABY, they invaded the New Republic.

Yuuzhan Vong War
Main Article: Yuuzhan Vong war

The Vong invaded the New Republic, crippling it and capturing its capital in 27 ABY. Refusing to surrender, the New Republic reformed into the Galactic Alliance, recaptured Coruscant, and forced the Vong into surrendering.

Post War
The Vong were forced to rebuild and reconstruct Coruscant, which they had partially terraformed. Afterwards, they went into self-exile in the Unknown Regions.