The Korsinite League was a political faction of the Lost Tribe of Sith on Kesh in the period of turmoil around 3000 BBY. They believed that Yaru Korsin and his daughter Nida Korsin were living gods, and adored them, believing that the first Grand Lord came from beyond, that the Lost Tribe of Sith was the body of the leader, and that those who would imperil the body deserved neither mercy nor life.
The Korsinite League was founded by a former slave, a century before 3000 BBY. He took Korsin as a title for himself, separate from the hierarchy of Lords, and patterned his life after those led by the first Grand Lord and his successor daughter. Then, he declared any worthy Sith could aspire to be like Korsin. His followers decided they could also adopt the title for themselves, which the movement's founder didn't want this, but it continued well after his death. Thus, all members of the cult had Korsin as their fist name. In addition, they also wore black uniforms.
By 3000 BBY, there were hundreds of Korsins of both sexes, who would chant mantras and declare their empire of one to anyone they could. Their rivals during the Time of the Rot included the Sisters of Seelah, Force 57, and the Golden Destiny. On that same year, Korsin Bentado and the League travelled to the Sith capital Tahv after they learnt that Iliana Merko, the leader of the Sisters, was trying to manipulate the Testament of Yaru Korsin prior to Testament Day. During that Testament Day, the assembled Sith factions discovered an earlier recording beneath Yaru Korsin's Testament which revealed that the early ancestors of the Lost Tribe were actually slaves of the Sith Lord Naga Sadow. This overturned the Tribe's popular mythology that their ancestors had been great conquerors.
This revelation sparked a series of violent riots and killings known as the Great Crisis, which devastated much of Keshtah Minor. The Korsinite League fought with their rivals before descending into infighting themselves. During the Crisis, Bentado lost his hand to Merko and vowed vengeance against the Sith woman. Later, Bentado joined forces with the surviving members of the Sith faction including Neera and Edell Vrai to destroy the ancient starship Omen in an attempt to destroy the "inglorious" heritage of the Sith. They were stopped by Caretaker Varner Hilts who revealed the existence of a second continent known as Alanciar. Hilts urged the Sith to commit themselves to reaching and conquering this new continent. Hilts was subsequently appointed as Grand Lord by the other Sith factions including the Korsinite League.
While many of the various Sith factions were dissolved during the Hilts Restoration, many former members of the Korsinite League still gravitated around Korsin Bentado, who had become a High Lord in Hilt's government. During the Invasion of Alanciar in 2975 BBY, the Ebon Fleet, a large fleet of sixty airships, was staffed by many former members and supporters of the Korsinite League. Many of these were killed when the Alanciari Keshiri shot down the Tribe's airships with ballistae. Bentado himself was killed following an unsuccessful attempt to kill Grand Lord Hilts and to establish a "Second Tribe" on Alanciar.