In the late nineteenth and early twentieth centuries, the vast majority of Lite's Jews were artisans and shopkeepers. Those who accumulated some capital went into lumber, one of the only big industries in the area. Despite czarist restrictions on education, a few middle-class Jews managed to enter the liberal professions, too, and with their degrees gained permission to work in cities outside the Pale of Settlement, beyond the restricted region in western Russia where Jews had been forced to live since the end of the eighteenth century. After World War I and the Russian Revolution, Lithuanian Jews found themselves living in the newly established Baltic states and in Poland. For a variety of reasons, including the rise of Polish anti-Semitism in the interwar years, many young Jews decided to study abroad and went to Germany and other countries in western Europe to take university degrees. Many never returned. Those who stayed behind engaged in a large number of businesses and professional enterprises, but by the early 1930s Jews living in Poland found it increasingly difficult to go to university and to take part freely in the economic life of the nation. Anti-Semitism did not enjoy political favor in independent Lithuania during the interwar years, but when the Germans invaded the country in 1941, "liberating" the republic from two years of Soviet occupation, thousands of Lithuanians joined the Nazis in their murderous campaign to rid Europe of Jews, a betrayal Lithuanian Jews still speak of with continuing surprise and bitterness.