Almost from the beginning, there were vast gulfs between the Hlutr of the Gathered Worlds and those of the Scattered Worlds. Scattered Worlds Hlutr, who sprang from seeds cast into the Galactic Halo in advance of Pylistroph Seed Vessels, were considerably more isolated than those of the Gathered Worlds. In addition, Scattered Worlds Hlutr tended to be much younger.
When the Gergathan proclaimed Mertorthar, most of the Hlutr in the Scattered Worlds disapproved -- while in the Gathered Worlds, a vast majority backed the new government. Many Gathered Worlds Hlutr, led by one of Messilinia who would later be known as The Eldest, accompanied the Daamin on their Flight into the Scattered Worlds.
In order to contain the evil of Mertorthar, and to shield the developing races of the Scattered Worlds, the Scattered Worlds Hlutr created the Curtain of the Hlutr, a screen of thought and mental song which surrounds the Galactic Core to prevent accidentally entering the Gathered Worlds. This Curtain effectively isolated the Core until Mertorthar's war against the Empire of the Iaranor about 600 million BCE.