Great Link

The Great Link was the intermingling of many Changelings in their natural liquid form, forming the ruling body of the Dominion. 

As the home of the Founders, the Link was effectively the "capital" of the Dominion. In 1879, the Great Link launched a Dominion attack against a group of El Aurian transport ships who attempted to colonize near their homeworld. This prompted a young shapeshifter to leave the Link and live among the solids in the Alpha Quadrant. (: "The Links' Traitor")