Second Battle of Deep Space 9

The Second Battle of Deep Space 9 was a battle which took place between Federation forces and the combined Cardassian/Dominion forces in 2373, and was the opening battle of the Dominion War. Gul Skrain Dukat led the combined Cardassian/Dominion force in the attack against Deep Space 9 and successfully captured the station from Federation control. Although it was a technical Dominion victory, the Federation ultimately succeeded because Captain Benjamin Sisko and his crew were able to mine the entrance to the Bajoran wormhole, and prevented Dominion reinforcements from entering the Alpha Quadrant. (DS9 episode: "Call to Arms").

Prelude to Battle
In mid-2373, Gul Dukat managed to negotiate the Cardassian Union's entry to the Dominion after a series of events had degraded the Union into a third-rate power such as the Klingon-Cardassian War and the continued Maquis threat. Once the treaty was signed, convoys of Dominion ships flooded from the Gamma Quadrant and entered Cardassian territory.

Almost overnight Cardassia was transformed thanks to their new allies. The Klingons were forced out from Cardassian territory and the Maquis were all-but wiped out by the Jem'Hadar with only a few pockets of resistance left in the Badlands. (DS9 episodes: "By Inferno's Light" and "Blaze of Glory").