8th Millennium BC
The Dominion was the major intestellar power in the Gamma Quadrant. Reigning over the region for millenia, the Dominion was controlled by the Founders, a species of shape-shifters or Changelings. The Founders genetically engineered other species, such as the Jem'Hadar, or genetically altered others, such as the Vorta, to serve as tools in their control over the Quadrant.
From 2373 to 2375, the Dominion invaded the Alpha Quadrant, in response to the Federation's continued exploration of Dominion-controlled space in the Gamma Quadrant. The Dominion allied itself with the Cardassian Union, and were later joined by the Breen Confederacy, against the allied forces of the Federation, the Klingon Empire and the Romulan Star Empire.
The war cost the Alpha Quadrant dearly, leading to millions of lives lost. Worlds such as Betazed were invaded and conquerred by the Dominion, and suffered greatly. Cardassia Prime was the theater of the final battle of the war, leading to the defeat of the Dominion forces in the Alpha Quadrant, and the Cardassian Homeworld was nearly destroyed as a result.
After the War
The Dominion retreated to the Gamma Quadrant following their defeat. Under the influence of the Founder Odo, the Founders withdrew their forces within the borders of Dominion space. The borders remain tightly sealed, and no sightings of Dominion ships have been reported since. The borders are guarded by a tight network of powerful defense turrents.
In 2395, the Dominion started withdrawing from the territories under its control. Worlds that had been rendered dependent on Dominion support were now left to fend for themselves. In other cases, local warlords have started appearing, trying to assert their control over an area of space that is now experiencing from a power vacuum.
There have been no Intelligence reports explaining the reason behind this sudden withdrawal. Some have speculated that the Dominion's attention could be turned toward a threat looming on the far side of Dominion space, while others hypothesize that the influence of the Founder known as Odo has led to a demilitarization of the Dominion. Indeed, since the Jem'Hadar are biologically incapable of procreation, if the Founders had ceased to clone Jem'Hadar soldiers, the species could be approaching extinction.
- Dominion borders are tightly sealed. Any ship crossing into their territory would be the target of defense turrets.
- New worlds are being abandoned by the Dominion, and are reaching out for assistance. Diplomatic missions are being dispatched from Opaka Outpost in an attempt to establish a Federation presence in the Quadrant.