The Defiant Class began as a response to the Borg threat. Development of this class began in 2365 with ships of this class being classified as escorts, but actually were small, heavily armed, highly powered warships. With a decrease in the Borg threat and design flaws found during the prototype's shakedown cruise, the project was abandoned by Starfleet. With the threat of a Dominion invasion of the Alpha Quadrant in 2371, Starfleet placed the Defiant in active status and sent it to Deep Space 9 as part of a first line defense for the Alpha Quadrant. The ship was equipped with pulse phaser cannons, quantum and photon torpedoes, and a cloaking device on loan from the Romulan Star Empire. The ship would have an exemplary service record including participation in: the Federation-Klingon War of 2372-73, the Borg invasion of 2373, and the costly Federation-Dominion War of 2373-75. Unfortunately, the prototype of the Defiant-class would be destroyed in late 2375, before the war with the Dominion ended. Another Defiant-class vessel, USS Sao Paulo, took the prototype's place at DS9 and fought in the final battles of the war as USS Defiant under special dispensation from Starfleet Operations.
