Jews had lived there for 800 years and represented about 10% of its population by 1933 when
the Nazis came to power. The three million Jews, the largest concentration any place in the world next to the U.S., considered themselves Jews whereas the Poles thought of them as Jews and not Poles.
Following World War I, Poland became independent and Polish nationalism was sparked. Poles viewed Jews as foreigners and anti-Jewish riots called “pogroms” took place. For example, in
August 1937, there were 400 attacks in 79 cities throughout Poland. About 60% of the Jews lived below poverty level, yet they were viewed as rising middle-class economic competitors.
Nobles like Prince Radzivil of Nesvizh tried to protect the Jews.