The Dominion's seizure and occupation of Deep Space Nine at the start of the Dominion War, ended when Starfleet retook the station in Operation Return.
The Dominion occupation of Deep Space Nine began late in 2373, at the outbreak of the Dominion War. To stop Dominion reinforcements reaching the Alpha Quadrant, Benjamin Sisko had the crew lay a field of cloaked, self-replicating mines across the mouth of the Bajoran wormhole. A large Dominion and Cardassian fleet attacked the station, and once the minefield was complete Sisko evacuated Starfleet personnel and abandoned it.
Gul Dukat and the Vorta Weyoun took control of the station, renaming it Terok Nor. Kira Nerys, Odo, Quark, Rom, Jake Sisko and others remained aboard. Kira, Rom and others formed a resistance cell, Rom was captured while trying to sabotage the station, and Odo was drawn away from his friends by linking with the Female Changeling. The Dominion meanwhile worked to bring down the minefield and open the way for its Gamma Quadrant fleet.
The occupation ran across six episodes and ended with Operation Return in 2374, when Starfleet and Klingon forces broke through to the station and the Prophets stopped the Dominion reinforcements in the wormhole.