Hebrew name: The Rebbe Maharash
Years: 1834–1882
Primary city: Lyubavichi
Rabbi Shmuel Schneerson was the fourth Rebbe of Chabad Lubavitch, succeeding his father, Rabbi Menachem Mendel Schneerson (the Tzemach Tzedek). He led the movement amidst internal challenges and external pressures from the Russian government. He originated the approach of "l'chatchila ariber" and engaged in extensive communal activism on behalf of Russian Jewry.