The word derives from the Hebrew "hesed" (kindness), and the appellation "hasid" (pious) has a history in Judaism for a person who has sincere motives in serving God and helping others. Some earlier Jewish movements were also called by this name, such as the Hasidei Ashkenaz of medieval Germany. However, today, the Hasidic philosophy and movement invariably refers to the mystical, populist revival of Judaism, initiated by Rabbi Israel ben Eliezer (The Baal Shem Tov) in 18th century Podolia and Volhynia (now Ukraine). His close disciples developed the philosophy in the early years of the movement. From the third generation, the select leadership took their different interpretations and dispersed across Eastern Europe, from Poland, Hungary and Romania, to Lithuania and Russia.