The Battle of Sybaron was fought during the Dominion War. The Starfleet Seventh Fleet was a main participant and was reduced to half its strength following the battle. (DS9: "Reckoning") After the Dominion's capture of Benzar they deployed a strike fleet to outflank several heavily-defended Federation star systems so they could stage an attack on Tellar. Starfleet Command deployed the Seventh Fleet with Klingon reinforcements to intercept the Dominion fleet before it could reach Tellar. The two fleets clashed at the little known Sybaron system.