Belgian prisoners of war in World War II  During World War II, Belgian prisoners of war were principally Belgian soldiers captured by the Germans during and shortly after the Battle of Belgium in May 1940.  225,000 men, approximately 30 percent of the strength of the Belgian army in 1940, were deported to prisoner of war camps in Germany. Large repatriations of prisoners, particularly of soldiers of Flemish origin, to occupied Belgium occurred in 1940 and 1941. Nevertheless, as many as 70,000 remained prisoners remained in captivity until 1945, and around 1,800 died in German camps during the course of the war. Belgian involvement in World War II began when German forces invaded Belgium, which had been following a policy of neutrality, on 10 May 1940. After 18 days of fighting, Belgium surrendered on 28 May and was placed under German occupation. During the fighting, between 600,000 and 650,000 Belgian men (nearly 20% of the country's male population at the time) had served in the military. King Leopold III, who had commanded the army in 1940, also surrendered to the Germans on 28 May along and remained a prisoner for the rest of the war. The Belgian government fled first to Bordeaux in France, and then to London in the United Kingdom where it formed an official government in exile in October 1940. In Belgium, an occupation administration, the Military Administration in Belgium and Northern France, was established in Brussels to run the territory under "Wehrmacht" jurisdiction. Virtually all the soldiers of the Belgian army who were not killed in action were captured at some point during the fighting in May 1940, but most of these prisoners were either released unofficially at the end of hostilities or escaped from poorly-guarded compounds in Belgium and went home. Escaped prisoners who returned home were rarely arrested by the Germans, and there was no systematic attempt to recapture former Belgian soldiers who had left German captivity in 1940. Shortly after the Fall of France, the remaining Belgian soldiers in captivity were deported to prisoner-of-war camps ("Kriegsgefangenenlager") in Germany, Austria and Poland. For the Germans, the Belgian prisoners represented a source of cheap labor which could be used in agriculture and factories after the conscription of most German workers. Belgian prisoners were again segregated by rank, with officers being sent to "Oflags" (an abbreviation for "Offizierslager") and NCOs and other ranks being sent to "Stalag" (or "Stammlager") camps.