United States Fifth Fleet
While the United States Fifth Fleet, whatever its mission, has always been a major command headed by a three- or four-star admiral, its role in the Second World War was totally different than its role today. Only the name is in common; even the geographical areas are different.
Second World War
During the Pacific War, the Navy maintained an exceptionally high tempo of operations. One of the enablers was developing extremely proficient underway replenishment to reduce dependence on shore bases, but the other was a novel approach to the top command.
The actual combat task forces, such as Fast Carriers Pacific Fleet, stayed at sea, with their own tactical and operational commanders. There were, however, two teams that took turns at the top command, luckily led by admirals who were close friends. United States Third Fleet was the command team under William Halsey, while Fifth Fleet was under Raymond Spruance.
When Third Fleet was conducting operations, Fifth Fleet staff were planning the next invasion. After the current operation ended, they exchanged roles. Fifth Fleet controlled the Battle of the Philippine Sea, for example, while Third Fleet ran the Battle of Leyte Gulf. Ironically, a number of naval analysts have suggested both battles, although U.S. victories, would have been even more decisive had the other team been in command — Spruance and Halsey had different styles.
Rather than the North, Central, and South Pacific, today's Fifth Fleet is the U.S. Navy regional command for the Middle East and Southwest Asia, the naval component of United States Central Command. Its current commander is Vice Admiral Mark Fox, who succeeded William Gortney.