The Great Calamity was an event remembered in the legends of the Keshiri species on the planet Kesh. The Calamity was caused by a massive conflict between the Protectors and the Destructors, resulting in the reshaping of the very surface of the world. The legends were based on Keshiri memories of an ancient conflict between Jedi and Dark Jedi who had become stranded on Kesh following the Hundred-Year Darkness.
They fought a fierce struggle which devastated large areas of Kesh's surface and terrorized the Keshiri natives. Eventually, the two warring factions decided to make peace and the Dark Jedi agreed to seal their "great weapon." These Force-users then migrated to the polar continent of Eshkrene in the planet's South Pole where they established a new neutral Force order which became known as "the Doomed."
The Dark Jedi were pursued by the Jedi outside the Stygian Caldera
The Great Calamity's roots can be traced back to the Hundred-Year Darkness, which marked a major schism between the orthodox Jedi and dark side-wielding Dark Jedi. These Dark Jedi pioneered the science of Sith alchemy and created various Sithspawn including the serpentine Leviathans, serpentine beasts which devoured the life energies of other beings. After decades of fighting, the Dark Jedi were defeated at the Battle of Corbos around 6900 BBY and the Jedi and Galactic Republic reasserted control over the galaxy.
Some Dark Jedi including Karness Muur, Remulus Dreypa, and XoXaan escaped the conflict and fled into the Stygian Caldera. These Dark Jedi discovered the planets Korriban and Ziost along with the native red-skinned Sith species. The Dark Jedi used their Force powers to take control of the Sith and created the first Sith Empire. Through this cross-cultural contact, the term Sith became synonymous with the dark side-wielding Sith Order, which would pose a major threat to the Jedi and the Republic in the preceeding millennia.
After a period of consolidation, Dreypa and several other exiles decided that it was time to leave the Stygian Caldera and take their revenge on the Jedi and the weakened Republic. Dreypa and his followers managed to acquired a large starship and several Leviathan larvae from the Sith Lord Sorzus Syn's laboratory on Korriban. Dreypa's ship managed to navigate its way out of the tricky Stygian Caldera. However, they encountered a group of Jedi veterans from Corbos who were still scouring the galaxy to hunt for their Dark Jedi opponents. After a pursuit across the galaxy, the Jedi and Sith ships crash landed on Kesh.
the Doomed migrating to Eshkrene
After landing on Kesh, the Jedi and Dark Jedi fought a fierce battle which would engulf the planet and threaten the indigenous Keshiri, a purple-skinned humanoid species. Kesh's unusual magnetic field prevented both sides from calling for reinforcements of leaving the planet. During the Great Calamity, Dreypa's Dark Jedi followers unleashed several great weapons including Leviathans which devastated much of Kesh's surface. Many Keshiri were killed and many settlements were destroyed during this fighting. Eventually, even Dreypa's Dark Jedi became disillusioned with the destruction they had wrought on Kesh.
With their leader Remulus Dreypa unable to see reason and end his quest for vengeance, his Dark Jedi followers sealed him within an oubliette where he would remain in stasis for nearly four millennia. The two rival Force orders then made peace and began a process of reconciliation. Since Kesh was still isolated from the rest of the galaxy, the Jedi and Dark Jedi agreed to withdraw from the Keshiri whom they had threatened. One Jedi starship also survived the conflict. Since the survivors had agreed that no one who was Force-sensitive could ever leave the planet, they decided to hide the vessel in the Keshiri burial cairns beneath the city of Tahv. However, they still preserved this knowledge in the event that they had to leave Kesh.
These Force users eventually traveled to the frozen continent of Eshkrene, which was situated in Kesh's South Pole. On Eshkrene, these former Jedi and Dark Jedi established a new community known as the Doomed who regarded Force-sensitivity as a curse rather than an extraordinary advantage. They sought to find true neutrality in the Force in order to balance both the light and dark sides. For four millennia, the Doomed and their descendants remained on Eshkrene. They would later use ice images to monitor the Lost Tribe of Sith, another group of stranded Force-users who arrived during the Great Hyperspace War.
The Doomed were the descendants of the Jedi and the Dark Jedi
The Great Calamity was not the only incident when Sith Exiles tried to threaten the Jedi and the Republic. Another conflict was fought between the Jedi and Sith prior to the Great Hyperspace War. However, in this case the Jedi won and and reported this news to the Jedi Council. The ancient Keshiri would remember the Great Calamity as a clash between two powerful groups of god-like entities known as the Protectors and Destructors. This became connected to an earlier Keshiri legend about the Skyborn, a powerful sandy-blooded race of god-like beings, who had fought against the malevolent Otherside—beings of fire, rebellion, sickness, and death—during the Great Battle.
In 5000 BBY, another group of Sith exiles from the Sith Empire became stranded on Kesh after their ship Omen was damaged during the Great Hyperspace War. Most of these Sith exiles were enslaved Human miners and ship crew who had been tasked with delivering a shipment of Lignan crystals to the Sith's Dark Lord Naga Sadow. By that period, the descendants of the Dark Jedi exiles had cohabited with the indigenous Red Sith and carved up a sizeable regional empire. However, contact with the Republic in 5000 BBY led to the Great Hyperspace War which culminated in the collapse of the Sith Empire.
Under the leadership of Yaru Korsin, the Human Sith assumed lordship over the Keshiri on Keshtah Minor by claiming that they were the legendary Protectors who had come down from the stars to visit their planet. These Sith became known as the Lost Tribe of Sith and would rule Kesh for several millennia. Despite their self-exile to Eshkrene, the Doomed still monitored developments in the other parts of Kesh. By 2975 BBY, the Lost Tribe under the leadership of Grand Lord Varner Hilts had annexed Alanciar and embarked on a maritime exploration program. This set in motion a chain of events in 2974 BBY which brought the Lost Tribe into contact with the Doomed.
The Great Calamity was first developed as a plot element by John Jackson Miller. It first appeared in Lost Tribe of the Sith—Spiral 2, the second issue of the Spiral comic arc, which debuted on September 12, 2012. The Great Calamity is occasionally mentioned through the arc which ended on December 12, 2012.