Shneur Zalman of Liadi, was an influential Lithuanian Jewish rabbi and the founder and first Rebbe of Chabad, a branch of Hasidic Judaism, then based in Liadi in Grand Duchy of Lithuania and later in the Grodno Governorate of 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 is a Yiddish composite of the two Hebrew words "shnei ohr".