The Battle of Cardassia was the final battle of the Dominion War, fought in late 2375. The Federation Alliance, the forces of the United Federation of Planets, the Klingon Empire, and the Romulan Star Empire, launched an invasion of the Dominion-held Cardassian Union, with the goal of capturing the Dominion's capital on Cardassia Prime. The battle would ultimately lead to the Dominion's unconditional surrender of all forces in the Alpha Quadrant.
The events of the battle must also be considered alongside concurrent events on Cardassia Prime in the final stages of the Cardassian Rebellion, led by Legate Damar. The sabotage committed by the Cardassian insurgents played an important role in disrupting Dominion communications and support behind the front lines, and ultimately led to the Cardassian military switching sides. Before the battle was over, however, more than 800 million Cardassian civilians would be killed by Dominion genocide, leaving the once-proud capital planet in ruins.