The Starfleet 11th Fleet was a military unit, a fleet group of the Federation Starfleet during the Dominion War. It was the unit in charge of protecting Benzar. After the Dominion invaded Betazed in 2374, a Dominion/Cardassian strike force arrived at Benzar and engaged the 11th fleet. After an hour of fighting, most of the 11th fleet's ships were destroyed. (RPG reference book: The Dominion War Sourcebook: The Fires of Armageddon)