ELIASBERG, MORDECAI (1817–1889), rabbi, one of the first *Ḥibat Zion (Ḥovevei Zion) in Russia. Born in Lithuania, Eliasberg studied under noted rabbis in Lithuania, became rabbi of Shishmory, Lithuania in 1853, and was rabbi of *Bauska, Latvia from 1862 until his death. Active from his youth in Jewish public life in Russia, he explained to Max *Lilienthal, who came to "enlighten" Russian Jewry, that the removal of legal restrictions on Jews was a prior condition to the achievement of this aim. Later he believed the basic principles behind Jewish demands should be the improvement of the economic situation of Russian Jewry and the achievement of equal rights. He supported the Haskalah movement, provided it did not weaken religion, and suggested the establishment of schools for commercial and vocational training. Eliasberg defended the first society for the settlement of Ereẓ Israel, founded in Germany in 1862, against attacks by ultra-Orthodox circles, who feared that messianic redemption would be delayed if the land was settled by secular efforts, and in 1879 he published articles supporting Jewish agricultural settlement in Russia and in Ereẓ Israel. After the pogroms in southern Russia (1881), Eliasberg was one of the first who vigorously supported the newly organized Ḥovevei Zion, orally and in writing, striving particularly to achieve harmony between the religious and the "free-thinking" circles in the movement. He was elected one of the leaders of Ḥovevei Zion at the movement's conference at Druzgenik (1887). During the controversy over the 1889 sabbatical year in Ereẓ Israel, Eliasberg opposed those ultra-Orthodox rabbis who demanded the cessation of Jewish agricultural work in that year and appealed to Jewish farmers not to heed their injunctions. He also strongly attacked the ḥalukkah methods in Jerusalem and those responsible for it, most of whom opposed the new settlement of Ereẓ Israel.
Of his more than 20 works, only one, Terumat Yad (1875), was printed in his lifetime. Shevil ha-Zahav, dealing with topical matters and the settlement of Ereẓ Israel, was published posthumously (1897) by his son Jonathan, who added a biography of his father. In 1947 a selection of Eliasberg's writings was published in Jerusalem.
His son jonathan (1851–1898) was born in Kovno, Lithuania, and served as rabbi of Pumpian, Mariampol, and from 1886 until his death, of Volkovysk, Grodno district. His Torah novellae and ethical writings were published as a supplement to his father's Terumat Yad and his Darkhei Hora'ah was published independently (1884). In common with his father, he was one of the first rabbis to join the Ḥovevei Zion movement. Eliasberg strove to maintain harmony between the Orthodox and the progressive groups within the national movement, calling upon both sides "to be tolerant and patient with conflicting views." In 1893 he approached *Aḥad Ha-Am in connection with his essay "Torah she-ba-Lev," which had aroused the anger of the Orthodox. (The author replied to the charges in his essay "Divrei Shalom.") His Zionist articles were published in Shivat Ẓiyyon (ed. by A.J. Slutski, 1900). After the first Zionist Congress, he joined the Zionist Organization.
N. Sokolow, Hibbath Zion (Eng., 1935), index; A.M. Genachowski, Ha-Rav Mordekhai Eliasberg (1937); I. Klausner, Be-Hitorer Am (1962), index; idem, Mi-Kattoviẓ ad Basel, 2 vols. (1965), indexes; ezd, 1 (1958), 111–21; M. Einhorn (ed.), Volkovisker Yizkor-Buch (1949), 71f.; Rabiner, in: Ba-Mishor, 4 (1942/43), nos. 136–7; I. Nissenbaum, Ha-Dat ve-ha-Teḥiyyah ha-Le'ummit (1920), 81–91.