Shneur Zalman

Shneur Zalman of Liady (שניאור זלמן מליאדי‎) (September 4, 1745 – December 15, 1812 O.S.), was an Orthodox Rabbi, and the founder and first Rebbe of Chabad, a branch of Hasidic Judaism, then based in Liadi, Imperial Russia. 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.

He is also known as the Baal HaTanya, "Master of the Tanya", and by a variety of other names including Shneur Zalman Baruchovitch, Baruchovitch being the Russian patronymic from his father Baruch, by the acronym RaZaSh, "Rabbi Za- Sh-", by the title Baal HaTanya ve-haShulchan Aruch, "Master of the Tanya and the Shulchan Aruch, as the Alter Rebbe ("Old Rebbe" in Yiddish), Admor HaZaken ("Old Rebbe" in Hebrew), Rabbeinu HaZokein, Rabbeinu HaGodol, "our great rabbi", the GRaZ, and Rav.