Short answers, pulled from the story.
Winston Churchill proposed the expulsion of Germans from Eastern Europe to Polish and Czechoslovak governments-in-exile in London in 1942. This idea grew from decades of ethnic nationalism that reshaped Central Europe after World War I.
The German Federal Archive estimated that 100,120,000 civilians died during this phase alone. Low-flying aircraft targeted some groups while others were crushed by tanks or died in winter conditions.
Allied leaders Franklin D. Roosevelt, Winston Churchill, and Joseph Stalin met at Potsdam between July 17 and the 2nd of August 1945. Article XII of their agreement recognized the transfer of German populations as necessary but demanded it be done orderly and humanely.
Between May and August 1945, 700,000 to 800,000 Germans faced irregular expulsions ordered by local armed volunteers and army units. Transfers under Potsdam agreements lasted until October 1946 sending 1.9 million ethnic Germans to the American zone and over 1 million to the Soviet zone.
A the 15th of June 1948 order halted expulsions followed by a the 25th of March 1950 decree voiding all orders. By January 1946 the first group of 5,788 departed from Wudersch after Soviet Commander-in-Chief ordered expulsions starting the 22nd of December 1944.