Jacob Emden
Jacob Emden, also known as Ya'avetz (June 4, 1697 April 19, 1776), was a leading German rabbi and talmudist who championed Orthodox Judaism in the face of the growing influence of the Sabbatean movement. He was acclaimed in all circles for his extensive knowledge. Emden was the son of the hakham Tzvi Ashkenazi, and a descendant of Elijah Ba'al Shem of Chełm. He lived most his life in Altona (now a part of Hamburg, Germany), where he held no official rabbinic position and earned a living by printing books. His son was Meshullam Solomon, rabbi of the Hambro Synagogue in London who claimed authority as Chief Rabbi of the United Kingdom from 1765 to 1780. The acronym Ya'avetz (, also written Yaavetz) stands for the words Yaakov (Emden) ben Tzvi (his father's name, ). Seven of his 31 works were published posthumously. Biography Jacob Emden (born Ashkenazi) was the 5th of his father's 15 children. Until the age of seventeen, Emden studied Talmud under his father Tzvi Ashkenazi, a foremost rabbinic authority, first at Altona, then at Amsterdam (1710–1714). In 1715 Emden married Rachel, daughter of Mordecai ben Naphtali Kohen, rabbi of Ungarisch-Brod, Moravia (the modern Czech Republic), and continued his studies in his father-in-law's yeshivah. Emden became well versed in all branches of Talmudic literature; later he studied philosophy, kabbalah, and grammar, and made an effort to acquire the Latin and Dutch languages, in which, however, he was seriously hindered by his belief that a Jew should occupy himself with secular sciences only during times it was impossible to study Torah. Career Emden spent three years at Ungarisch-Brod, where he held the office of private lecturer in Talmud. Later he became a dealer in jewelry and other articles, an occupation which compelled him to travel. He generally declined to accept the office of rabbi, though in 1728 he was induced to accept the rabbinate of Emden, from which place he took his name. He returned to Altona in, where he obtained permission from the Jewish community to possess a private synagogue. Emden was at first on friendly terms with Moses Hagis, the head of the Portuguese-Jewish community at Altona, who was afterward turned against Emden by some calumny. His relations with Ezekiel Katzenellenbogen, the chief rabbi of the German community, were positive at first, but deteriorated swiftly. A few years later Emden obtained from the King of Denmark the privilege of establishing at Altona a printing-press. He was soon attacked for his publication of the siddur (prayer book) Ammudei Shamayim, due to his harsh criticisms of the powerful local money changers. His opponents did not cease denouncing him even after he had obtained for his work the approbation of the chief rabbi of the German communities. According to Jacob Katz, "Rabbi Jacob Emden: Life and Major Works" (Jacob J. Schacter, unpublished PhD dissertation, Harvard University, 1988), "supplanted" Mortimer J. Cohen's 1937 book Jacob Emden: A Man of Controversy, as the most authoritative source on Emden. Ya'a'vetz pen name In