, which became the sole national flag in 1935. New York: Penguin Books. Overy argues that the bombing strained the German war economy and forced it to divert up to one-fourth of its manpower and industry into anti-aircraft resources, which very likely shortened the war. Conquest of Europe Against the advice of many of his senior military officers, Hitler ordered an attack on France and the Low Countries, which began in May 1940. In February 1941, the German Afrika Korps arrived in Libya to aid the Italians in the North African Campaign. During the war, Poland lost an estimated 39 to 45 percent of its physicians and dentists, 26 to 57 percent of its lawyers, 15 to 30 percent of its teachers, 30 to 40 percent of its scientists and university. Many POWs starved to death or resorted to cannibalism while being held in open-air pens at Auschwitz and elsewhere. A Concise History of Nazi Germany. Warsaw: Państwowe Wydawnictwo Naukowe. A vast security network spied on the activities of clergy and priests were frequently denounced, arrested or sent to concentration camps many to the dedicated clergy barracks at Dachau. These laws initially prohibited sexual relations and marriages between Aryans and Jews and were later extended to include "Gypsies, Negroes or their bastard offspring". More than a thousand people (out of a population of around 16,000) committed suicide in Demmin on and around the 65th Army of 2nd Belorussian Front first broke into a distillery and then rampaged through the town, committing mass rapes, arbitrarily.