Jews moved to Eastern Europe in the 13th and 14th centuries.
This led to hundreds of years of Jews thriving in the Eastern side of Europe as opposed to Western and Central Europe where anti-semitism was rampant for centuries.
Poland was truly a wonderful place for many years.
The spiritual center of Israel was clearly Poland for centuries.
Perhaps the most fascinating aspect of the spiritual growth that took place in Poland was the birth of the Hasidic movement.
This movement gradually became one of the most dominant movements throughout the Jewish communities worldwide.