The earliest presence of U.S. Navy forces in Europe was the Mediterranean Squadron, the European Squadron following the American Civil War, the forces were combined as part of the North Atlantic Fleet in 1906. In 1917, United States Naval Forces Operating in European Waters developed as a command under the leadership Admiral William S. Sims to oversee the European aspects of United States Navy operations during World War I. His principal subordinates were Rear Admirals Henry B. Wilson in France and Albert P. Niblack at Gibraltar.