ROSENBAUM, SEMYON (Shimshon ; 1860–1934), jurist and Zionist. Born in Pinsk, Rosenbaum practiced law there and in Minsk. In 1880s he joined the *Ḥibbat Zion movement, and was a delegate to the Zionist Congresses until World War i. At the Fourth Congress in 1900, he was elected to the Zionist General Council and served as a delegate of the Zionist center to the Minsk district. He organized the *Minsk Conference of Russian Zionists in 1902. Rosenbaum's point of view was close to that of the *Democratic Fraction in the Zionist Organization, and he helped to organize the first *Po'alei Zion groups in the Minsk district in Lithuania. He was among the leaders of ẓiyyonei Zion, who actively opposed the *Uganda Scheme. At the *Helsingfors Conference in 1906, he was made a member of the Zionist central committee of Russia.
Rosenbaum held a central position in the League for the Attainment of Legal Rights for the Jews in Russia. He was elected to the first Russian *Duma in 1906 and joined the liberal Constitutional-Democratic ("Kadet") faction. When the Duma was dissolved, he was among those Duma members who signed the manifesto calling for civil disobedience and nonpayment of taxes and was sentenced to prison. After his release, he engaged in providing legal assistance to pogrom victims and to Zionists persecuted by the Russian authorities. After the outbreak of World War i, Rosenbaum moved to Vilna and was elected head of the Zionist organization there. He participated in the negotiations with the Turkish government concerning the future of Palestine after the war (1918). He also took part in the establishment of independent Lithuania in 1919. He was deputy minister of foreign affairs in the first Lithuanian government and a member of its delegation to the Versailles Peace Conference. He signed the peace treaty with the Soviet Union on behalf of the Lithuanian Republic. He was a member of the commission that drafted the Lithuanian Republic's constitution, which granted the Jews wide national autonomy. Rosenbaum was the president of the National Council of the Jews in Lithuania and in 1923 became minister of Jewish affairs. In 1924, after the annulment of the Jewish autonomy, he went to Palestine, where he engaged in public activities in *General Zionist circles. He was chairman of the supreme Jewish peace court, and one of the founders of the Tel Aviv School of Law and Economics. He wrote many essays on Zionist and juridical subjects, including his research Der Souveraenitaetsbegriff (1932).
M. Sudarsky and U. Katzenellenbogen (eds.) Lite (Yid., 1951), index; Ch. Leikowicz (ed.), Lite, 2 (Yid., 1965), index; Tidhar, 3 (1949), 1317–18.