Rabbi Shneur Zalman Fradkin was born in Adar 5590 (1830) in Liadi to Shlomo and Eidel, and was named after the founder of Chabad, Rabbi Shneur Zalman of Liadi, whose town it was.

A devoted disciple of the Tzemach Tzedek, the third Lubavitcher Rebbe, he also studied after his marriage under Rabbi Eliyahu Yosef of Dribin. The Tzemach Tzedek held him in high esteem, calling him a gaon and involving him in the affairs of the beit din. His memory was famous, and it is said that he never forgot anything he had learned.

He had resolved not to earn his living from the rabbinate, but after losing all his possessions (according to one source, when a fire ruined his wealthy father-in-law), he was appointed rabbi of Polotsk in 5615 (1855) at the Tzemach Tzedek's instruction. In 5628 (1867-1868) he became rabbi of Lublin, earning the title "Gaon of Lublin." After his teacher's passing he worked for the continuation of Chabad in Lubavitch under his son, the Rebbe Maharash.

In the summer of 5652 (1892) he moved to Jerusalem, where he founded the rabbinical court of the Chassidic community (Kollelot HaChassidim), separate from that of the Perushim. For a time he served as rabbi of the Chassidic community, and people came to him for blessings.

Works: his responsa Toras Chessed, of which the section on Orach Chaim appeared in Warsaw in 5643 (1883) and the section on Even HaEzer after his death; his writings on Yoreh Deah and Choshen Mishpat were lost. He passed away in Jerusalem on 5 Nissan 5662 (1902) and is buried in the Chabad section of the Mount of Olives. He was the grandfather of Yitzhak Sadeh, the first commander of the Palmach.