Polish Jews

The history of Jews in Poland is worthy of its own entry. A legend has it that a Jew was instrumental in starting the Piast dynasty, the first dynasty of Polish rulers. Later in XIV Century, last of the Piast kings was a great supporter of Jewish immigration (knowing him, he was mostly interested in the female half). Polish Jews were listed as a separate class alongside nobility, clergy, peasantry and townsfolk and had broad autonomy, and their skills were held in high regard by the ruling noblemen, who often employed them as managers and tax collectors. A stereotypical image of a Jew from that period is the innkeeper. The Hasidic Jews got their start there.

While there was that separateness or occasional Blood Libel, the Jews did not have it bad. Poland up until it's dissolution in the late 18th century was a mess in terms of ethnicity and these kinds of conflicts could be seen between any of the major groups. That said, when someone rose against the nobility (like the Cossacks did), the Jews had it bad, due to the aforementioned link.

The situation deteriorated during XIX Century with the advent of nationalism, though, as the nationalists believed that the Jews compete economically with Poles. Shortly before Second World War, some of the more radical ones went for introducing the limits for Jews admitted to universities, and even, we kid you not, came up with ridiculous plan of shipping them to Madagascar. That period also saw the rise of assimilation movement, Jews taking up Polish culture while retaining their religion—ironically they were hated the most by the nationalists.

Then the War happened. Many Poles - just look up Righteous among the Nations - did help the Jews, but there were some nasty types, too. Polish underground even had a special agency, called Żegota, whose agenda was to help Jews.

After the war, 1968 saw the anti-Semitic madness engineered as a result of infighting in the Party, where one faction wanted to get rid of the other, happening to include many Party-members of Jewish descent. It resulted in these Jews who managed to survive the Holocaust depart (often forcibly) to Israel and other countries.

As for Israel itself, many of its early prominent politicians hailed from Poland, most notably its first Prime Minister (and foremost founding father), David Ben-Gurion. Reportedly, many early debates in the Knesset were even held in Polish (presumably when debate got heated and the MKs started sipping in their native tongues).

There's also an important issue that deserves mention: Polish anti-Semitism. These of Poles who have issues with Jews often exhibit a mix of primitive pre-War-kind and belief in Jewish involvement in Communism. Before the War, many Jews took a interest in left-wing ideologies, whose doctrine didn't make a fuss about their Jewishness - after all, why wouldn't one of the most persecuted minorities be affiliated with an ideology which promised freedom and liberation? (The reality, however, varied, as was evidenced by '68.) It didn't help that poor old Karl Marx was himself ethnically Jewish (although raised a Lutheran and when an adult a firm atheist). After the War, many Party members were (or were perceived to be) of Jewish descent, and while it generally makes no difference, it makes one to these people. The Western perception of Polish anti-Semitism is mostly due to Polish Jews' unpleasant memories of pre-War times, wartime and 1968, as to the fact that some of the more vocal Polish emigree circles hailed from conservative and nationalist Jew-unfriendly environments. As always, one should watch out for the Vocal Minority.