Yom Tov Lipmann Heller   Yom Ṭov Lipmann ben Nathan ha-Levi Heller, (b. 1579, Wallerstein, Bavaria [Germany]—d. Sept. 7, 1654, Kraków, Pol.), Bohemian Jewish rabbi and scholar who is best known for his commentary on the Mishna. His works also indicate that he had extensive knowledge of mathematics, the sciences, and other secular subjects. Raised by his grandfather Moses Wallerstein, a respected rabbi, Heller studied at the yeshiva of Judah Loew ben Bezalel and was appointed a dayan (judge) in Prague at the age of 18. He served as a rabbi to communities in Moravia and Vienna, but he was recalled to Prague in 1627 to the office of the chief rabbinate. At this time, because of involvement in the Thirty Years’ War, the Holy Roman emperor Ferdinand II had imposed heavy taxes on the Jews of Bohemia. As chief rabbi, Heller was responsible for overseeing the collection of the tax, a task that aroused bitter opposition within the Jewish community and made him the object of false accusations. Charged with contemning both the state and Christianity, he was heavily fined and briefly imprisoned; he was also forbidden to serve the rabbinate anywhere within the empire. Later, while serving as a rabbi in Vladimir, Volhynia, Pol., Heller again became the centre of controversy. At a rabbinical conference known as the Council of the Four Lands, he fought for the renewal of a decree preventing the purchase of rabbinical offices, simony being a practice at that time. This aroused the anger of some of the wealthier Jews, who succeeded in obtaining a decree from the governor ordering Heller’s expulsion. Although the decree was eventually rescinded, in 1643 Heller accepted an appointment to the chief rabbinate in Kraków, where he lived the remainder of his life. Among Heller’s many written works are an autobiography, Megillat eyva (“Scroll of Hate”; first published in 1818), which documented the various communities in which he had lived and included accounts of massacres of Jews in Prague (1618) and the Ukraine (1643). The most famous of his many religious works is his commentary on the Mishna, Tosafot Yom Ṭov (1614–17, 2nd ed. 1643–44; “The Additions of Yom Ṭov”). Heller’s commentary was intended to serve as a supplement to the commentary of Obadiah of Bertinoro; both works are found in many modern editions of the Mishna.