Joel ben Samuel Sirkis (Hebrew: רבי יואל בן שמואל סירקיש; born 1561 - March 14, 1640) also known as the Bach (an abbreviation of his magnum opus BAyit CHadash), was a prominent Ashkenazi posek and halakhist, who lived in central Europe and held rabbinical positions in Belz, Brest-Litovsk and Kraków, and is considered to be one of the greatest Talmudic scholars of Poland. He is known for his liberal rulings in his responsum in which he challenges the rabbinic status quo. Biography Born in Lublin, Poland in 1561, his father Samuel Sirkis was a rabbi in Lublin and his mother Sarah Jaffe was a member of the Jaffe family, through her father Moses Jaffe of Kraków, making Mordecai Jaffe, the Bach's second cousin. At age fourteen he went to the yeshiva of Naftali Zvi Hirsch Schor, a leading student of Moses Isserles. After remaining there for some time he went to Brest-Litovsk, where he attended the yeshiva of Rabbi Phoebus. While still in his youth, he was invited to the rabbinate of Pruzhany. He later occupied the rabbinates of Lukow, Lublin, Medzyboz, Belz, Szydlowka, and Brest-Litovsk, finally settling in Kraków in 1619, where he married Bella, the daughter of Abraham of Lwow and was appointed Av Bet Din of Kraków and head of the yeshivah. Many of his students became leading rabbis in Poland, the most famous being his son-in-law, David ben Samuel ha-Levi, as well as Gershon Ashkenazi and Menachem Mendel Krochmal. In 1631 he wrote his magnum opus, Bayit Ḥadash (lit "new house"), a critical and comprehensive commentary on the Arba'ah Turim of Jacob ben Asher, in which he traced each law to its Talmudic source and followed its subsequent development through successive generations of interpretation. His work received the approval of the greatest rabbinic scholars of his time, even those outside of Poland. The Bach was also an adherent of Kabbalah, yet he rejected kabbalistic practices that were contrary to the halakhah. He was also critical of those who relied solely on the Shulchan Aruch for halachic decisions, rather than on the Talmud and the Geonim. The Bach's responsum provides a concise overview of the social and economic conditions of Polish Jewry, as well as the relationship between Jews and non-Jews in early 17th century Poland. One of his responsa, in particular, was censored by the Christian authorities because the work addresses the case of a Jew