The European Theatre of World War II, also known as the European War, was a huge area of heavy fighting across Europe, from Germany's and the Soviet Union's joint invasion of Poland in September 1939 until the end of the war with the Soviet Union conquering much of Europe along with the German unconditional surrender on May 8, 1945 (Victory in Europe Day). The Allied forces fought the Axis powers on two major fronts (the Eastern Front and Western Front) as well as in the adjoining Mediterranean and Middle East Theatre.