Construction on the Relentless began at Utopia Planitia Fleet Yards in 2373, as part of a wave of Defiant-class vessels ordered by Admiral James Leyton. The ship was not completed until after the Federation Civil War, and was launched in 2375.
|Defiant class escorts|
|Canon: Defiant (I) - São Paulo/Defiant (II) - Valiant (I)|
|Other notable ships: Alexander - Avenger - Boxer - Dauntless - Defender - Devastation - First Strike - Gallant - Grant - Horwitz - Imperial - Indomitable - Maelstrom - Man-o-War - Merrimac - Monitor - Nemesis - Nimitz - Relentless - Renown - Sinclair - Stormbringer - Svelor - Ticonderoga-A - Tirpitz - Valiant (II) - Victorious - Victory - Vindicator - Vulture - Warrior|