German prisoners of war in northwest Europe
More than 2.8 million German soldiers surrendered on the Western Front between D-Day (June 6, 1944) and the end of April 1945; 1.3 million between D-Day and March 31, 1945; and 1.5 million of them in the month of April. From early March, these surrenders seriously weakened the Wehrmacht in the West, and made further surrenders more likely, thus having a snowballing effect.
Source: Wikipedia — German prisoners of war in northwest Europe (CC BY-SA 4.0)