Yechezkel ben Yehuda Landau

Yechezkel ben Yehuda Landau (8 October 1713 – 29 April 1793) was an influential authority in halakha (Jewish law). He is best known for the work Noda Biyhudah (נודע ביהודה), by which title he is also known.
Biography

Landau was born in Opatów, Poland, to a family that traced its lineage back to Rashi, and attended yeshiva at Ludmir and Brody. In Brody, he was appointed dayan (rabbinical judge) in 1734, and in 1745 he became rabbi of Yampol. While in Yampol, he attempted to mediate between Jacob Emden and Jonathan Eybeschütz in a debate - "The Emden-Eybeschütz Controversy" - that "had disrupted Jewish communal life for many years". His role in the controversy is described as "tactful" and brought him to the attention of the community of Prague - where, in 1755, he was appointed rabbi. He also established a Yeshiva there; Avraham Danzig, author of Chayei Adam, is amongst his best known students.

Landau was highly esteemed not only by the community, but also by others; and he stood high in favor in government circles. Thus, in addition to his rabbinical tasks, he was able to intercede with the government on various occasions when anti-Semitic measures had been introduced. Though not opposed to secular knowledge, he objected to "that culture which came from Berlin", in particular Moses Mendelssohn's translation of the Pentateuch.
Works

His main work of responsa, titled Noda Biyhudah (נודע ביהודה, "Known in Judah", a reference to Psalms 76:2 and his father's name), is one of the principal sources of Jewish law of his age. Famous decisions include those limiting autopsy to prevent a clear and present danger in known others. This collection was esteemed by rabbis and scholars, both for its logic and for its independence with regard to the rulings of other Acharonim as well as its simultaneous adherence to the writings of the Rishonim.

Other works include Dagul Mervavah on the Shulkhan Arukh (cf. Song of Solomon 5:10) and Tziyun le-Nefesh Chayah (abbreviated as Tzelach, named in reference to his mother, whose name was Chayah) on the Talmud.
External links

Ezekiel ben Judah Landau, jewishencyclopedia.com
Yechezkel Landau — The Nodah Biyehudah, jewishvirtuallibrary.org
Rabbi Ezkiel Landau (5473-5553; 1713-1793), chabad.org
Archive of www.nodabyehuda.com
Dagul Mervavah
HaNoda Bihudah Umishnato
Noda Bihudah, Prague, 1776
Noda Bihudah Kamma, New York, 1960
Noda Bihudah Tanina, New York, 1960
Ziun L'nefesh Chaya on Brachot
Ziun L'nefesh Chaya on Beitza
Ziun L'nefesh Chaya on Psachim