ROSENTHAL, LEON (Judah Leib ; 1817–1887), Russian financier, maskil and philanthropist. Rosenthal was born into a wealthy family in Vilna. His father, Moses, one of the first maskilim in Vilna, educated him in the spirit of the *Haskalah. After his marriage, he went to live in Brest-Litovsk. When Moses *Montefiore visited Russia in 1846, Rosenthal submitted to him a memorandum claiming that education and modern schools would solve the problems of Russian Jewry. In the 1850s, Rosenthal settled in St. Petersburg, where he became associated with the *Guenzburg family and was one of the city's leading financiers and bankers. He corresponded with maskilim all over Russia, assisting them in their dealings with the government, distributing their literature, and also supporting them financially. In 1863 Rosenthal was among the founders of the *Society for the Promotion of Culture among the Jews of Russia; he served as the society's treasurer, contributed largely to its budget, and participated actively in its work. Advocating the spread of Hebrew language and literature and opposing assimilationist trends, he was influential in the society's support of Hebrew journals and books. In his later years, he began to write the history of the society, Toledot Ḥevrat Marbei Haskalah be-Yisrael be-Ereẓ Rusyah (2 vols., 1885–90), which also contains records and documents from the society's archives and is of great value for the history of the Haskalah in Russia. He was also one of the founders of the society for promotion of crafts and agriculture among Jews in Russia, ort, and was one the main contributors to the society.
J.L. Kantor, in: L. Rosenthal, Toledot Ḥevrat Marbei Haskalah, 2 (1890), introd.; E. Tcherikower, Istoriya Obshchestva rasprostraneniya prosveshcheniya sredi yevreyev, 1 (1913), passim.