The Baal Shem Tov
Rabbi Israel Baal Shem Tov, also known by the acronym Besht, is considered the founder of Chassidic Judaism, a movement based on spiritual revival and mysticism. Before revealing himself as a mystic leader, the Baal Shem Tov headed a secret group of hidden mystics who studied Torah and practiced the service of G-d with a focus on mysticism.
The Baal Shem Tov was born on August 21 1698 (18 Elul 5458). He passed away on May 21, 1760 (6 Sivan 5520). He is buried in Medzhybizh, in present-day Ukraine.
The Chabad scholar R’ Hillel Paricher testified in the name of his teacher R’ Mordechai of Chernobyl, who heard from his father the Maor Einayim, that on the 18th of Elul the Besht was born in body, spirit and soul. In body—his physical birth. In soul—when his holy teacher and mentor revealed himself to him. And in spirit—when he was revealed to the Jewish people.