The Immigrant Fleet is an organization that wishes to control the Zohar. In Episode II, the Immigrant Fleet is led by a man called Sergius XVII, who is also the leader of the secret society Ormus. Essentially, the Immigrant Fleet can be seen as the public organization, while Ormus can be seen as the secret organization. This is why Jin Uzuki says in Episode II, "Why would the leader of the Immigrant Fleet be here?" It serves as the public persona and military arm of the highly secretive Ormus.
Highly religious and powerful, the Immigrant Fleet claims to have been the guardian of the Zohar "since time immemorial." According to Sellers, all members of the Immigrant Fleet have at least some affinity to the waves from the Zohar.
The Immigrant Fleet were the survivors who escaped Lost Jerusalem (Earth) before it was sealed away. They used an immigrant ship called Pleroma (an asteroid base was named after it) and settled on planet Abraxas (which would later be named Michtam).
The groups formed an independent nation unaffiliated with Federation law, and thus declared the establishment of the Immigrant Fleet nation. However, it was later incorporated into the Federation.
Rule over Abraxas Edit
In the T.C. 4500s, the Immigrant Fleet appears in the Michtam star system and claimed sovereignty over planet Abraxas, their "holy land". A protracted conflict between the two groups started in the Michtam system not long after.
In the T.C. 4600s, the territorial rights of Abraxas went to the Immigrant Fleet.
Zoar Incident Edit
The Zoar Incident occurred in T.C. 4730. It was rumored that extremists among the people of the Immigrant Fleet who lived chiefly among the planets of the Miltian System and Zoar, had feared Miltia joining the Federation.
Miltian Conflict Edit
The Immigrant Fleet was involved in the Miltian Conflict and the space-time anomaly that sealed off Miltia.
Xenosaga Episode II: Jenseits von Gut und Böse Edit
The Immigrant Fleet's military arm, U-TIC, gained access to the Y-Data that Joachim Mizrahi left behind, employing both political maneuvers and outright brute force. Though they succeeded in unlocking the way to Old Miltia, the Immigrant Fleet suffered a major defeat when the Zohar and the Omega System were activated, which destroyed the Immigrant Fleet forces as well as the Federation and Miltian taskforces sent to stop them. The Patriarch himself was later eliminated by the Testaments after being abandoned by his Ormus subordinates.
Episode III database Edit
One of the space fleets that escaped Earth when Lost Jerusalem disappeared. During an extended period of nomadic existence, the fleet's scope expanded and split apart, and each splinter fleet emigrated to a newly discovered settlement area.
At the start of the T.C. 4000s, it reunited with another fleet that had escaped from Earth--a group that had already formed a united organization of nations in the form of the Galaxy Federation. The two groups began mutual exchanges, but their backgrounds and cultural disparities were too much to bridge. Most importantly of all, the Immigrant Fleet was in possession of the Zohar. This led to a history of wars and truces that has repeated itself countless times.
In the story, the Immigrant Fleet is mostly perceived as identical to Ormus, but this is not always true. The influence of Ormus doctrine has been diluted among some Immigrant Fleet splinter groups, and many have begun their own form of self-rule. These groups have advanced a policy of reconciliation with the Federation, and they would later join the Federation organization. It would appear that the Immigrant Fleet does not consist entirely of pious worshipers swearing allegiance to Ormus.