Galactic History 31: The Ritual of Nathema
During the final days of the Great Hyperspace War, the Sith Emperor and his closest followers remained upon a world known as Nathema and did not engage the Republic. It is clear from the records that Nathema is not the original name of the world, but why it was changed and why he was there has been carefully purged from all records.
What is known is that following the flight of Naga Sadow, the Emperor came to Korriban, gathered the remaining lords of the Sith and took them back with him to Nathema. There they conducted a ritual that extended the Emperor’s life at the cost of the lives of more than eight thousand Sith Lords. The Ritual of Nathema is celebrated among Imperial scholars as a rare and amazing coming together of Sith for the good of the Empire.
The Emperor then gathered the younger generation of Sith, promoted new lords and promised them revenge on the Republic for its attempted genocide of the Sith people. Aboard a small fleet, the Sith Empire vanished into unknown space, leaving no trace for the Republic to find.
Galactic History 32: Long Exile
Led by their new Emperor, the survivors of the Sith Empire had left Korriban aboard a small fleet following the Great Hyperspace War. There was no place in known space they could hide from the Republic–and so, undaunted, they fled into the unknown regions of the galaxy.
Where the old Sith Empire had often been divided by rivalries, the survivors were now united, both by their desire to find a new home and by their anger at the Republic that had sought to destroy them. For decades, the fleet wandered among the stars–until one day, a scout vessel returned to the armada with incredible news.
Either by luck or by the esoteric designs of the often-silent Emperor, the Sith had rediscovered a long-lost outpost world: the jungle planet of Dromund Kaas. Absent from any star charts, Dromund Kaas presented a perfect refuge where the Sith Empire could rebuild and plan its revenge.
Galactic History 33: Dromund Kaas
Once an outpost of the ancient Sith Empire, the planet Dromund Kaas now presented a refuge to the Empire's weary survivors after their long exile from Korriban. Upon landing, the Emperor addressed the populace, promising them that from this world, a new civilization would grow to eventually crush the Republic.
The challenges of colonizing such a wild planet were soon evident. Dromund Kaas's jungles were untamed. full of dangerous predators. To ensure order and discipline, military service became mandatory for non-Force sensitives. Imperial citizens took pride in this duty, knowing they were defending the future of their people.
Before withdrawing into isolation, the Emperor established a Dark Council to oversee the Empire and control the hierarchy of the Sith. He is said to have conducted many dark side rituals and experiments that affected the planet itself, leaving Dromund Kaas storm-wracked to this day.
Galactic History 34: The Discovery of Ryll
In the years after the Great Hyperspace War, a discovery was made on the Twi'lek homeworld of Ryloth - the spice called ryll. Ryll was a component in several medicines, but was also a powerful stimulant. Sensing opportunity, Neimoidian traders quickly gained a monopoly on ryll and were keen to introduce it to other species.
One of these species was the Porporites, a peaceful people who had recently made first contact with the Republic. But in contrast to other species, ryll drove the Porporites into homicidal fury. Eventually, the entire species was composed of raging maniacs who began attacking other worlds.
Alarmed, the Republic asked the Jedi to take action against the Porporites, but the intervention was unsuccessful. The Neimoidians, fearing for their livelihoods, decided more desperate measures might be necessary and turned to Gank mercenaries for help.
Galactic History 35: The Gank Massacres
Addicted to the spice ryll-which drove them into a murderous frenzy-the Porporite species had become a threat to the galaxy. The Neimoidians had a monopoly on ryll and, terrified of the coming Porporite swarm, turned to the Ganks to stop the Porporites quickly.
The Ganks were mysterious, cybernetic mercenaries that often worked for the Hutts. With the Ganks' reputation as cold-blooded killers, the Neimoidians were confident they could handle the Porporite armies. But the Ganks' solution was to eliminate the entire Porporites species, and they hunted the Porporites to extinction.
Encouraged by this "success," the Ganks began wiping out other species, quickly becoming a far greater threat than the Porporites. The Jedi took up arms against them, but Supreme Chancellor Vocatara was forced to commission the first juggernaut droids to end the Gank menace for good.