Designed in 2366, the Defiant was the first of what was to be a new class of heavily-armed Federation starship. Officially designated an escort, the Defiant-class was specifically designed to counter the Borg. Soon after the first vessel was completed however, a combination of a less urgent Borg threat and several design flaws caused Starfleet to suspend the project. Among the flaws was the fact that the Defiant's engines were overpowered relative to the size of the ship—so much so that the Defiant nearly "tore itself apart" during its shakedown cruise.
The USS Defiant, originally USS São Paulo, was a Defiant-class escort assigned to Deep Space 9 in the final weeks of the Dominion War. It was one of at least three Federation starships to carry the name Defiant, and the second Defiant-class ship to bear the name.
