Question: What is the other name  for a huge area of heavy fighting across Europe with the Soviet Union having occupied and annexed several countries effectively handed over by Nazi Germany?

The General Government (German: "Generalgouvernement" , Polish: "Generalne Gubernatorstwo" , Ukrainian: Генеральна губернія ), also referred to as the General Governorate, was a German zone of occupation established after the joint invasion of Poland by Nazi Germany and the Soviet Union in 1939 at the onset of World War II.  The newly occupied Second Polish Republic was split into three zones: the General Government in its centre, Polish areas annexed by Nazi Germany in the west, and Polish areas annexed by the Soviet Union in the east.  The territory was expanded substantially in 1941 to include the new District of Galicia. <SEP>  These included Eastern Poland (incorporated into two different SSRs), as well as Latvia (became Latvian SSR), Estonia (became Estonian SSR), Lithuania (became Lithuanian SSR), part of eastern Finland (became Karelo-Finnish SSR) and eastern Romania (became the Moldavian SSR and part of Ukrainian SSR).  Apart from Molotov–Ribbentrop Pact and post-war division of Germany, USSR also occupied and annexed Carpathian Ruthenia from Czechoslovakia in 1945 (became part of Ukrainian SSR). During World War II, the Soviet Union occupied and annexed several countries effectively handed over by Nazi Germany in the secret protocol Molotov–Ribbentrop Pact of 1939. <SEP> Upon the defeat of Nazi Germany in World War II, the victorious Allied powers asserted their joint authority and sovereignty over 'Germany as a whole', defined as all territories of the former German Reich which lay west of the Oder–Neisse line; having declared the extinction of Nazi Germany at the death of Adolf Hitler (see 1945 Berlin Declaration).  The four powers divided 'Germany as a whole' into four occupation zones for administrative purposes, creating what became collectively known as Allied-occupied Germany (German: "Alliierten-besetztes Deutschland" ).  This division was ratified at the Potsdam Conference (17 July to 2 August 1945).  In autumn 1944 the United States, United Kingdom and Soviet Union had agreed on the zones by the London Protocol.  The powers at Potsdam approved the detachment from 'Germany as a whole' of the German eastern territories east of the Oder-Neisse line; with the exact line of the boundary to be determined at a final German Peace Treaty.  This treaty was expected to confirm the "shifting westward" of Poland's borders (back to approximately as they were before 1722), as the United Kingdom and the United States committed themselves to support there the permanent incorporation of former eastern German territories into Poland and the Soviet Union.  In the closing weeks of fighting in Europe, United States forces had pushed beyond the agreed boundaries for the future zones of occupation, in some places by as much as 200 mi .  The so-called line of contact between Soviet and American forces at the end of hostilities, mostly lying eastward of the July 1945-established inner German border was temporary.  After two months in which they had held areas that had been assigned to the Soviet zone, U.S. forces withdrew in the first days of July 1945.  Some have concluded that this was a crucial move that persuaded the Soviet Union to allow American, British and French forces into their designated sectors in Berlin, which occurred at roughly the same time (July 1945), although the need for intelligence gathering (see Operation Paperclip) may also have been a factor. <SEP>  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. The European theatre of World War II, also known as the Second 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).