||The best known of Landau's works, He-Arukh u-Musaf he-Arukh im Ma'aneh Lashon, is the talmudic dictionary by R. Nathan b. Jehiel with a German translation. Addition t.p.: Rabbinisch- aramaeisch- deutsches Woerterbuch zur kenntniss des Talmuds, der Targumim und Midraschim; mit Anmerkungen... von M. I. Landau...
Moses Landau (1788–1852), printer, publisher, and lexicographer. Born in Prague, grandson of R. Ezekiel Landau, Moses was imbued with the traditional atmosphere of his rabbinical family. At the same time, he devoted himself to secular studies, especially German literature. He established a Hebrew printing press in Prague, which, for more than two decades, published sacred literature along with some contemporary Hebrew works, including several volumes of the scholarly periodical Kerem Hemed. From 1831 until his death he was head of the Prague Jewish community and was instrumental in bringing Solomon Judah Rapoport there to serve as rabbi. From 1849 he served on the Prague municipal council. His other works are Pitron ha-Millot (Prague, 1827), which deals with the difficult terms found in the Torah; an edition of the Hebrew Bible, with a German translation and a Hebrew commentary on several books (1834–38); a German translation of the mahzor with a Hebrew commentary; the kinot for the Ninth of Av; the Passover Haggadah; and Marpe Lashon (Odessa, 1865), a collection of the foreign words in Rashi's commentary on the Bible and the Talmud.
R. Nathan b. Jehiel of Rome (1035–c. 1110), Italian lexicographer, also called Ba'al he-Arukh ("the author of the Arukh") after the title of his lexicon. Few biographical details are known of him. Some state that he belonged to the De Pomis or Delli Mansi family, but the view is widespread that he actually belonged to the famous Anau (Anav) family. He was taught in his youth by his father, a paytan and the head of the yeshivah of Rome, and may as a young man have studied in Sicily under R. Mazli'ah b. Elijah ibn al-Bazak, a pupil of R. Hai Gaon. However, there is reason to believe that the scanty references to Mazli'ah's name in Nathan's work are the addenda of an earlier copyist named Mevorakh, some of whose marginal notes, in which he also mentions that he was Al-Bazak's pupil, were later incorporated in the text of the Arukh. R. Nathan also studied under R. Moses ha-Darshan of Narbonne, as well as, in the view of some scholars, under R. Moses Kalfo of Bari and R. Moses of Pavia. When his father died immediately after Nathan's return to Rome about 1070, he and his two brothers Daniel and Abraham succeeded him as the heads of the yeshivah of Rome. With them he wrote responsa to halakhic questions addressed to him by various scholars, among whom was a R. Solomon Yizhaki, identified by some as Rashi. Noted for his charitable acts, Nathan built a magnificent synagogue and a ritual bathhouse for his community. It was while serving as head of the Rome yeshivah that he wrote his classical work (which he completed in 1101) the Arukh, a lexicon of the Talmud and the Midrashim, containing all the talmudic terms in need of explanation; in the course of time various additions were made to it (see below). At the end of the Arukh there is a poem written in particularly difficult language and therefore of somewhat obscure meaning; in it the poet, lamenting his bitter lot, tells of the death of four out of his five sons during his lifetime.