The USS Nimitz was an Akira class heavy cruiser serving in Starfleet during the 24th century.
In 2373 she was serving in the Typhon Sector.
On stardate 50893.5 the Nimitz was docked at Deep Space Five when a Borg cube was detected. Fleet Admiral Skinner came aboard, declared it his flagship and set off to engage the cube, along with the USS Lionheart and the USS Oi. Other ships would rendezvous enroute.