Russian family of scholars and philanthropists. Its founder was Abraham Landsberg of Kremenetz, who was born in 1756 and died in 1831 of the plague, then raging in Russia. He had six sons who were among the first Russian Maskilim. Of these, the eldest, Aryeh Löb Landsberg (1780-1861), lived at Odessa, and was an able writer in Hebrew and a prominent merchant. Through business reverses he lost his fortune, and for the rest of his life lived in reduced cirumstances and seclusion, devoting his time to study. David Judah Landsberg, the youngest son of Abraham, was principal of the public school for Jewish children at Odessa. Of Abraham's other sons, Lippe Landsberg and Mendel Landsberg (1786 to Jan. 8, 1866) lived at Kremenetz, where they were born. Mendel was the more prominent, not only for his learning, but also for his charitable disposition. He had a remarkable collection of books, most of which, after his death, were incorporated in the Friedland collection now in the Asiatic Museum at St. Petersburg. Mendel contributed some articles on Biblical subjects to "Ha-Karmel" and other Hebrew journals, and wrote "Sefer ha-Ḳundes" and other satirical pamphlets.
The members of the Landsberg family were intimate with Isaac Bär Levinsohn, and Mendel Landsberg placed his library at Levinsohn's disposal, the collection being of inestimable value for the latter's literary work. In a fit of anger Levinsohn made a scurrilous attack on Landsberg in the form of a Talmudic treatise entitled "Massekta Oto we-Et Beno"; but they ultimately became reconciled.
- Ha-Meliẓ, 1861, No. 31; 1866, No. 5;
- I. B. Levinsohn, preface to Teudah be-Yisrael, Wilna and Grodno, 1828;
- Shorashe Lebanon, pp. 259 et seq., Wilna, 1841;
- S. Wiener, Bibliotheca Friedlandiana, Preface, St. Petersburg, 1893.