The Yaavetz

Rabbi Yaakov Emden (1697–1776) was a towering halakhic authority and prolific author of the Ashkenazi world in eighteenth-century Altona, Hamburg, and Wandsbeck. Son of the renowned Chacham Tzvi, Emden inherited both his father's erudition and combative temperament. He authored dozens of works spanning halakha, homiletics, kabbala, and history, most famously his Mor u-Ketzia (a supercommentary on the Shulchan Aruch) and his Siddur Beit Yaakov. Emden is remembered as a fierce opponent of what he perceived as Sabbatian heresy, most notably in his prolonged dispute with Jonathan Eybeschütz over the latter's amulets. A restless scholar and polemicist, he combined meticulous legal reasoning with passionate defense of rabbinic tradition and Ashkenazi practice.