Helena was queen of Adiabene and wife of Monobaz I. With her husband she was the mother of Izates II and Monobaz II. She died about 56 CE. Her name and the fact that she was her husband's sister  indicate a Hellenistic origin. Helena became a convert to Judaism about the year 30 CE.
She was noted for her generosity; during a famine at Jerusalem she sent to Alexandria for corn (grain) and to Cyprus for dried figs for distribution among the sufferers from the famine. In the Talmud, however (B. B. 11a), this is laid to the credit of Monobaz; and though Brüll regards the reference to Monobaz as indicating the dynasty, still Rashi maintains the simpler explanation—that Monobaz himself is meant. The Talmud speaks also of important presents which the queen gave to the Temple at Jerusalem. "Helena had a golden candlestick made over the door of the Temple," to which statement is added that when the sun rose its rays were reflected from the candlestick and everybody knew that it was the time for reading the Shema'. She also made a golden plate on which was written the passage of the Pentateuch which the high priest read when a wife suspected of infidelity was brought before him. In Yerushalmi Yoma iii. 8 the candlestick and the plate are confused. The strictness with which she observed the Jewish law is thus instanced in the Talmud: "Her son [Izates] having gone to war, Helena made a vow that if he should return safe, she would become a Nazirite for the space of seven years. She fulfilled her vow, and at the end of seven years went to Judah. The Hillelites told her that she must observe her vow anew, and she therefore lived as a Nazirite for seven more years. At the end of the second seven years she became impure, and she had to repeat her Naziriteship, thus being a Nazarite for twenty-one years. Judah ha-Nasi, however, said she was a Nazirite for fourteen years only." "Rabbi Judah said: 'The sukkah [erected for the Feast of Tabernacles] of Queen Helena in Lydda was higher than twenty ells. The rabbis used to go in and out and make no remark about it'."
Helena moved to Jerusalem, where she is buried in the pyramidal tomb which she had constructed during her lifetime, three stadia north of Jerusalem. The catacombs are now called the "Tombs of the Kings." A sarcophagus with the inscription Tzara Malchata, in Hebrew and Syriac, found in the nineteenth century, is supposed to be that of Helena.
The royal palace of Queen Helena is believed to have been discovered by archaeologist Doron Ben-Ami digging in the City of David in 2007. The palace is a monumental building located in the City of David just to the south of the Temple Mount. The remnants of ancient frescoes can be seen. The basement level contained a Mikveh. It was destroyed by the Romans in 70 CE. The ruins contained datable coins, stone vessels and pottery. 
- ↑ Josephus, "Ant." xx. 2, § 1.
- ↑ Josephus, l.c. § 5.
- ↑ "Jahrb." i. 76.
- ↑ Yoma 37a.
- ↑ Yoma 37b; Tosefta Yoma 82
- ↑ Numbers v.19-22
- ↑ Yoma l.c.
- ↑ Nazir 19b.
- ↑ Suk. 2b.
- ↑ comp. Eusebius of Caesarea, Ecclesiastical History ii., ch. 12.
- ↑ "C. I. S." ii. 156.
- ↑ Israeli archaeologists uncover 2,000-year-old mansion 06/12/2007 
- ↑ Dec 5, 2007 | Updated Dec 24, 2007 Second Temple palace uncovered By ETGAR LEFKOVITS , Jerusalem Post, 
- Gottheil, Richard and M. Seligsohn. "Helena". Jewish Encyclopedia. Funk and Wagnalls, 1901-1906, which cites:
- Josephus, Jewish Antiquities xx. 4, § 3;
- Brüll's Jahrb. i. 70-78;
- Grätz, Heinrich, Gesch. 3d ed., iii. 403-406, 414;
- Schürer, Gesch. 3d ed., iii. 119-122.
- This article incorporates text from the 1901–1906 Jewish Encyclopedia, a publication now in the public domain.