Hasidism, an eastern European movement of religious pietism (the word hasidut means piety), has played a key role in Jewish life for the last 250 years. Starting in the mid-18th century, it infused the Jewish religion with new values by democratizing access to the divine and created a new social structure around wonder-working rabbis (rebbes or zaddikim). It also excited intense opposition, first among the Polish-Lithuanian rabbinical elite, which, in turn, devised new cultural values in order to refute Hasidism. In the 19th century, it became the target of sustained attacks by the new movement of Jewish enlightenment (Haskalah), which also developed its ideology at least partly in contradistinction to Hasidism. Despite these opponents, Hasidism gradually became the most influential religious movement among eastern European Jews by the mid-19th century. However, its power was eroded by the forces of modernization, urbanization, and emigration and it was dealt a near-death blow by the Holocaust. Nevertheless, the remnants of the movement reconstituted themselves, particularly in the new state of Israel and North America to the point where Hasidism has now once again become a force to be reckoned with in Jewish religious life.
A Hundred Years of Yiddish Song Mobility