Rabbi Shneur Zalman of Liadi (1745-1812) was a prominent Jewish leader and the founder of the Chabad movement, a branch of Hasidic Judaism. He is best known for his philosophical writings, particularly the Tanya, which outlines the principles of Chabad thought and emphasizes the importance of serving God with both intellect and emotion. Rabbi Shneur Zalman was also a respected halachic authority, and his teachings focused on the integration of Jewish law with mystical concepts. His influence extended beyond his lifetime, as his followers continued to spread his teachings, establishing Chabad-Lubavitch communities worldwide.