Shneur Zalman, Russian rabbi, author and founder of Chabad (d. 1812)
Shneur Zalman of Liadi (Hebrew: שניאור זלמן מליאדי, September 4, 1745 – December 15, 1812 O.S. / 18 Elul 5505 – 24 Tevet 5573), was an influential rabbi and the founder and first Rebbe of Chabad, a branch of Hasidic Judaism, then based in Liadi in the Russian Empire. He was the author of many works, and is best known for Shulchan Aruch HaRav, Tanya, and his Siddur Torah Or compiled according to the Nusach Ari. Zalman is a Yiddish variant of Solomon and Shneur (or Shne'or) is a Yiddish composite of the two Hebrew words "shnei ohr" (שני אור "two lights").
Zalman of Liady is also known as "Shneur Zalman Baruchovitch," Baruchovitch being the Russian patronymic from his father Baruch, and by a variety of other titles and acronyms including "Baal HaTanya VeHaShulchan Aruch'" (Author of the Tanya and the Shulchan Aruch), "Alter Rebbe" (Yiddish for ″Old Rabbi″), "Admor HaZaken" (Hebrew for ″Our Master, Our Teacher, and Our Old Rabbi″), "Rabbenu HaZaken" (Hebrew for ″Our Old Rabbi″), "Rabbenu HaGadol" (Hebrew for ″Our Great Rabbi″)", "RaShaZ" (רש"ז for Rabbi Shneor Zalman), "GRaZ" (גר"ז for Ga'on Rabbi Zalman), and "HaRav" (The Rabbi, par excellence).