The Catpire was an empire that was ruled by the Catporer. Most of its citizens were cats. They overtook several planets during and after the Clone Wars, during which time they were part of the Invasion of the Catpire.
After the Clone Wars ended and the Galactic Empire came to power, the Catpire helped the Empire fight against the Rebel Alliance, taking a number of Rebel planets and bases. After the Empire fell, the Catpire helped the New Republic during the Yuuzhan Vong invasion. They took back Coruscant from the Yuuzhan Vong.
The Catpire was in an alliance with the Katpire, an empire about the same size and was also made of cats.
The Catpire owned over 300 planets in the Unknown Regions, and they soon took over the Chiss. As the New Confederacy of Independent Systems took over the New Republic, the Catpire laid low in the Unknown Regions massing an army, along with the Katpire, which took years of planning and preparation. They then found the leaders of the New Republic who hide in the Unknown Regions, and made an alliance with them. The Two Empires were now over 50,000,000 strong (not counting the Navy), and were prepared for Invasion. The New CIS never considered that the Catpire would be a threat. They never even knew that they existed.
After the New CIS's disastrous and humiliated defeat at the Colonies, more governments supported the Catpire, Katpire, New Republic, and Imperial Remnant, who became known as the Allies. Allied forces soon took the Core Worlds and got help from the local Core Worlds militias, that were rebellious and were raiding the New CIS convoys. Catperial assassins were sent to hunt down the members of the Separatists Council, which they did quickly. Soon, the New Republic regained the control of the Galaxy, and the Outer Rim was given to the Two Empires as a thanks.
In the years following, the Catpire gained more technology. Among some of tech was an advanced radar that scanned near by galaxies. In one of the nearest galaxies, and large cluster of oddly shaped asteroids was discovered. After an analysis, it was discovered that they are actually large ships. They were in fact Yuuzhan Vong ships, ready for invasion of the known galaxy. The Catpire sent several Star Destroyers to the New Republic capital, but by the time they got there, the Vong begun their attack on several New Republic systems. After a while, they reached Coruscant and a large battle broke out.
The Catpire had two branches, the Army and the Navy. Both of these branches had a number of standing orders:
Behind the scenes
Cats in the Catpire were originally supposed to not use blasters and not be an advanced race, but clans of wild animals.