The Starfleet Fourth Fleet was a numbered fleet in the United Federation of Planets Starfleet, active in the 23rd and 24th centuries. The Fourth Fleet was commanded by Admiral T'Pam aboard USS Achernar ca. 2285. (Starfleet International) The Fourth was involved in the Battle of Rumarda where they lost 54 starships and 13,200 personnel in the early part of the Dominion War. (The Dominion War Sourcebook: The Fires of Armageddon)