The Yamaguchi was part of the Federation Fleet that engaged the Borg at Wolf 359 in 2367. The Yamaguchi was part of the wave that included the USS Bellerophon. The Yamaguchi was badly damaged in the battle. (DS9 episode: "Emissary") Years later, after having been rebuilt, the Yamaguchi fought in the Dominion War with the Twelfth Fleet. In 2375, she successfully breached the Dominion line in the Battle of Betazed. (Decipher RPG module: Starships)