Yuuzhan/Destructor–Chiss War

The Yuuzhan-Chiss war was a war that took place in the Outer Rim Territories in 1,000,000,000 BBY before the formation of the Galactic Republic or anything else. The Vong tried to take the galaxy and would have if they hadn't ran into a Chiss scout patrol. The Chiss attacked the Vong and forced them out of the galaxy, and united the Chiss clans to form the Chiss Empire, though the Vong promised to return, and they did over several thousand years later, and the Chiss Empire took part in defeating them again.