Onias IV (Hebrew: חוֹנִיּוֹ Ḥōniyyō) was the son of Onias III and the lawful heir of the legitimate high priests. He had reason to hope that the victory of the national party under Judas Maccabeus would place him in the office of his fathers; but being disappointed in his expectations by the election of Alcimus, he went to Egypt to seek aid against the tyranny of the Seleucids at the court of the Ptolemies, their political enemies. About 154 BCE, with the permission of Ptolemy VI Philometor, he built at Leontopolis a temple which, though comparatively small, was modelled on that of Jerusalem, and was called by the name of its founder. Onias doubtless expected that after the desecration of the Second Temple by the Syrians the Egyptian temple would be regarded as the only legitimate one. But the traditional teachings of Judaism, as contained in the Mishnah, concede no legitimacy to the temple of Onias; in fact, even for the Egyptian Jews the latter did not possess the same importance as did the Temple of Jerusalem.
Onias IV, who enjoyed the favour of the Egyptian court, succeeded in elevating Egyptian Judaism to a position of dignity and importance. A large number of able-bodied Judeans had accompanied Onias to Egypt, and these strangers, who were there called Κάτοικοι ("inhabitants"), received, on condition of performing military service and preserving the internal peace of the country, tracts of land of their own, on which they lived with their families The district inhabited by them lay between Memphis and Pelusium, and was long called the "land of Onias." The first-born sons of the colonists inherited their fathers' privileges and duties; but both Chelkias ben Onias and Ananias ben Onias, the sons of Onias, performed military service and acted as generals under Cleopatra III (who reigned from 117 to 81 BCE). Even Ptolemy Physcon (who reigned from 146 BCE to 117 BCE) had to fight against Onias, who was faithful to his benefactor. This suggests that candidates for the office of high priest occupied a prominent military position. In the course of time the family of Onias lost its prestige, and the later Alabarchs belonged to another family, not entitled to the rank of high priest. A family of "Oniades," in the sense of "Tobiades," as the term is used by Büchler, existed neither in Judea nor in Egypt, and the designation "Oniades" is, therefore, misleading.
- Menahot chapter 13, mishna 10 - "The priests who served in the house of Onias may not serve in the Temple in Jerusalem, and it needs not be said [if they served] a different thing [i.e. pagan idols]"
- "Ant." xi. 8, § 6; see Paul Meyer in "Philologus," 1897, lvi. 193
- "Ant." xiv. 8, § 1; "B. J." i. 9, § 4)
- "Ant." xiii. 10, § 4
- (Josephus, "Contra Apion" ii. 5
- Gottheil, Richard and Samuel Krauss. "Onias." Jewish Encyclopedia. Funk and Wagnalls, 1901–1906, which cites to the following bibliography:
- H. P. Chajes, Beiträge zur Nordsemitischen Onomatologie, p. 23, Vienna, 1900 (on the name);
- Herzfeld, Gesch. des Volkes Jisrael, i. 185-189, 201-206;
- Heinrich Grätz, Gesch. 2d ed., ii. 236;
- Emil Schürer, Gesch. 3d ed., i. 182, 194-196; iii. 97-100;
- Niese, in Hermes, xxxv. 509;
- Wellhausen, I. J. G. 4th ed., p. 248, Berlin, 1901;
- Willrich, Juden und Griechen vor der Makkabäischen Erhebung, pp. 77, 109, Göttingen, 1895;
- Adolf Büchler, Die Tobiaden und die Oniaden, pp. 166, 240, 275, 353, Vienna, 1899;
- J. P. Mahaffy, The Empire of the Ptolemies, pp. 217, 353, London, 1895;
- Gelzer, Sextus Julius Africanus, ii. 170-176, Leipsic, 1885;
- Isaac Hirsch Weiss, Dor, i. 130 (on the halakic view of the temple of Onias).