In 2373, the Valiant was assigned as the training vessel for the elite Red Squadron and sent on a three-month cruise to circumnavigate the Federation. During its cruise the Dominion War broke out and the ship quickly found itself behind enemy lines. While trying to return to Federation territory it was engaged by a Cardassianbattle cruiser, the Valiant destroyed the battle cruiser though at the cost of the ship's officers, leaving the vessel under the command of Cadet Tim Watters.
Watters then undertook the captain's secret orders to track and collect data on the new Jem'Hadar battleship. After several months the Valiant managed to fulfill its mission, Watters then decided to attempt to destroy the battleship by shooting a modified torpedo at the antimatter storage system's primary support braces. During the engagement the Valiant was destroyed, only three people onboard managed to escape alive. (DS9: "Valiant")