The world where the shapeshifting Founders of the Dominion gather as the Great Link, first found in the Omarion Nebula and later moved to a rogue planet.
The Founders' homeworld is the planet where the Changelings who rule the Dominion live together as the Great Link, a vast ocean of shapeshifters merged into one being. Its location is one of the Dominion's most closely guarded secrets. In 2371 Odo, drawn by a deep sense of where he came from, found it inside the Omarion Nebula in the Gamma Quadrant, and learned that his own people were the Founders.
Later that year a joint Romulan and Cardassian fleet attacked the homeworld, hoping to wipe out the Founders with one blow, but the planet had been abandoned and the fleet was destroyed in a Jem'Hadar ambush. The Founders settled on a new world, a rogue planet, where they later judged Odo for killing another Changeling and turned him into a solid. Section 31's disease eventually spread through the Great Link, and after the Dominion War Odo returned to cure his people.
The homeworld sits at the heart of Deep Space Nine's Dominion story. It is where Odo faced the choice between his people and his friends, and where the Founders' fear of solids was made clear.