Shneur Zalman of Liadi (the Alter Rebbe)

Founder of Chabad: the Maggid's student who built Hasidism's most intellectual wing — ecstasy through structured contemplation (hitbonenut), the mind as the heart's bridle, Tanya as the manual. Arrested twice on informers' charges (his release date, 19 Kislev, is celebrated as the "Rosh Hashanah of Hasidism"). The lineage he founded now runs the most globally distributed Jewish infrastructure on earth.