Yaakov Emden

Rabbi Yaakov Emden, also known by his initials as Ya'avetz, was a German rabbi, talmudist, and polemicist, son of another well-known scholar known as the Chakham Tzvi. In addition to his scholarship, Rabbi Emden is known for his public campaign against Rabbi Jonathan Eybeschutz, whom he accused of being a secret follower of the disgraced messianic hopeful, Shabbetai Tzvi. He published many works, including a prayer book with extensive commentary, a collection of responsa entitled Sheilat Ya'avetz, and annotations on the Talmud.