The Defiant is a prototype and is therefore the only one in its class. It was originally designed to fight the Borg, and there were plans for a fleet of these ships to make up a Starfleet battle fleet. Work began in 2266 when the Federation was alerted to the Borg and following the battle at Wolf 359, Captain Benjamin Sisko was assigned to supervise the work at the Utopia Planitia Fleet Yards on Mars. However, after a shakedown cruise, serious problems came to light, and the work on the Defiant was suspended.

The Defiant was put on active duty when Starfleet learned of the threat posed by the Dominion from the Gamma Quadrant. The Defiant is assigned to Captain Sisko at Deep Space Nine, the first line of defence against the Jem'Hadar (the soldiers of the Dominion). The Defiant is found docked on the outer ring to Deep Space Nine when not being used on a mission. Security is high because of the advanced technology in the Defiant - armed guards are posted at the airlock and voice print identification is required to gain access.
 
Specific Data:
 
 

Class	Defiant
Built	Utopia Planitia Yards, orbiting Mars
Commissioned	2371
Captain	Benjamin Sisko