Odo
From FEInfobase
Odo former chief of security on station Deep Space Nine returned to the Great Link in 2375 and soon became a leader for the Dominion.
On May 12 2380 Odo travelled to the Alpha Quadrant and offered the United Federation of Planets and the Klingon Empire ever lasting peace from the Dominion. The offer was relunctly accepted and two weeks later the Alpha and Gamma Accords were signed.
January 1st 2386 saw the Federation Alliance in heavy combat with the Borg. The Dominion agreed to assist their former enemy as they saw the Borg as a possible threat to the Gamma Quadrant as well. Later on in the month Odo along with several other representives from the Federation Alliance signed a formal treaty where the Dominion agreed to assist in the war against the Borg. They set up bases in the Dreon system and the Sol System
In May of 2388 the Borg launched a massive offensive against Dominion forces in the Gamma Quadrant. The Borg destroyed the Founder's Homeworld and forced the Dominion to retreat to the Alpha Quadrant. The Dominion soon became Federation members electing Odo as its chief representive on the Federation Council.
In January 2404, Councillor Odo made an unscheduled but highly publicised trip to Bajor. (SFC: "A Tale of Two Cities")