rabbi and preacher, the first theoretician and literary propagandist of Jewish Ḥasidism.

Jacob Joseph was a rabbi in the large Jewish community at Shargorod, in Podolia; after he came under the influence of the Baʿal Shem Ṭov, the founder of Ḥasidism, he was expelled (c. 1748) from Shargorod. He was subsequently rabbi of Rashkov, Nemirov, and ultimately Polonnoye, where he remained until his death.

As a writer, he contributed significantly to the spread of Ḥasidism. His first and main work was the controversial Toldot Yaʿaqov Yosef (1780; “History of Jacob Joseph”), which not only related the teachings of the Baʿal Shem Ṭov but also criticized traditional Jewish leadership and values. The work thus provoked anti-Ḥasidic sentiment and was burned by some opponents of the movement. Other works include homilies and commentary on books of the Bible, including Ben Porat Yosef (1781; “Joseph Is a Fruitful Vine”) on Genesis; Ẓefenat Paʾneʾaḥ (1782) on Exodus; and Ketonet Passim (“Coat of Many Colours”) on Leviticus and Numbers.