The Dominion

A powerful alliance of peoples, mostly in the gamma quadrant.
The Domion was created 2,000 years ago by a shape-shifting species called the Founders.
The Founders remain hidden from view, but their policy is excercised by the Jem'Hadar, their warriors.
Jem'Hadar are known to be ruthless with those who do not comply.
In one example, the inhabitants of a planet from the system Telpas was striken with a disease called the
blight and caused generations of suffering.
The Founders are an anceient civilization that explored the galaxy.
In their voyages, they were found to be feared and hunted by the solids (non-shape-shifters).
They retreated to an uninhabited planet in the Omarion Nebula. There, they could meld together
in liquid forms to create was is called the Great Link - a collective of matter and thought.
From this remote location, they created the Dominion.
They sent many of their own kind throughout the galaxy as infants, expecting that one day they would return to
the homeworld and report their experiences abroad. Among these was Deep Space Nine's chief security officer, Odo.
At one point, the Founders created the Jem'Hadar, a genetically-engineered species of fighters, to enforce the Dominion's will.
The Jem'Hadar have a low life expectancy, and require an isogenic enzyme called ketracel-white, or simply "white."
White is provided to them by the Vorta, a race belonging to the Dominion.
Since Jem'Hadar deal strictly through the Vorta, few have actually seen Founders.
They are seen among the Jem'Hadar as legends or gods.
When the Bajoran wormhole was discovered in 2369 by the Federation, many people from
the alpha quadrant began establishing themselves in Dominion space. Among these Starfleet exploration teams, Bajoran settlers and Ferengi traders.
The Dominion sent a definite message by taking out the New Bajor colony.
The Dominion sent agents to infiltrate alpha quadrant governments, many of them Founders.
These agents, such as an imposter of Klingon General Martok, attempted to destabilize
the politics in the quadrant, to make them more susceptable to a Dominion takeover.
In 2373, the Dominion made a pact with the Cardassian Union, clearly establishing themselves in the alpha quadrant.