Rabbi Elozor ben Yehuda, famed author of the Sefer Rokeach, codifier, Tosafist and Kabbalist, was born, it is believed, in Mayence, in or about the year 4920 (1160). He came from a long line of leading Rabbis.

Rabbi Elozor was a disciple of Rabbi Yehuda HaChassid, under whose guidance he studied the Talmud and the Kabbala.

Mayence had one of the oldest leading Jewish communities in Europe. Here it was that the great luminary Rabbenu Gershon Meor HaGolah ("Light of the Exile") headed his Yeshiva two centuries earlier. It was one of the three sister communities, known as SHUM - a word formed from the Hebrew initials of the names of the cities: Speyer, Worms and Mayence. The great Rashi also studied at the Yeshiva of Mayence.

Rabbi Elozor ben Yehuda settled in Worms, where Rashi lived two generations earlier. Here Rabbi Elozor devoted all his time to the study of the Torah and to his writings, while his wife Dultza took care of the business and family affairs. During the third Crusade (1196), a terrible tragedy struck the happy family of Rabbi Elozor. It was three days before Chanukah, while Rabbi Elozor was sitting at his desk, engaged in his writings, that two murderous villains burst into his home. They killed Rabbi Elozor's wife, their two daughters, Belet, thirteen years old, and Chana, six years old, as well as a young son and his teacher. Rabbi Elozor himself was severely wounded, but he survived.

This was a very cruel blow for Rabbi Elozor. He mourned his family, and the loss of his wife was particularly felt by him, for she was an extraordinary woman, wise and learned, very charitable and hospitable, especially to Torah scholars.

Rabbi Elozor overcame this terrible tragedy and continued to devote himself to his studies, writings and the affairs of his community. In 1226 he joined with Rabbeinu Tam and Rabbi Shmuel (Rashbam)-Rashi's grandsons-in instituting certain Takanoth (ordinances) to regulate the religious and economic life of Jewish communities. Three years later he was among the leading Rabbis who convened in Mayence and issued the so-called Takanoth SHUM - ordinances for the three communities of Speyer, Worms and Mayence. These were later accepted by all Jewish communities in Germany.

Rabbi Elozor was one of the outstandingTosafists of his day. The Tosafists were the leading Talmud scholars who composed commentaries to the Talmud, called Tosfos ("additions") in addition and as supplement to the great commentary of Rashi. Rabbi Elozor of Worms was one of these great Talmud scholars who not only helped expound and explain the Talmud, but also recorded and edited these commentaries.

Rabbi Elozor was a prolific writer, who composed some thirty works in Halachah, Kabbalah, Jewish philosophy, ethics, and explanations of the various books of the T'NaCh.

Most famous of his works was the Sefer Rokeach ("Compound of Spices"), so called because the numerical value of the Hebrew word Rokeach (consisting of the three letters Resh, Kuf, and Ches) is the same as that of his name Elozor -308. The Rokeach is a code dealing with the whole range of Jewish laws. It contains the laws of Shabbos and of all Yomim Toivim (festivals), and other laws and customs of the Jewish home and Jewish daily life, such as the laws of marriage, mourning, dietary laws, and so forth. Like the Code of Maimonides (Rambam), the Rokeach opens with a number of chapters in which the author explains basic principles of our faith, such as the love of G‑d, the unity of G‑d, repentance, and so forth. These chapters, as well as all his writings, reflect the deep piety and saintliness of the author. This book was first published in Fano (Italy), in the year 1505.

Rabbi Elozor also wrote commentaries on the prayers, chiefly in the spirit of the Kabbala. He was a Paytan of renown. He composed many piyutim, slichos (penitential prayers), kinos (lamentations), and personal prayers for various occasions.

Many of Rabbi Elozor's works were lost, or remained in part, mostly in manuscripts.

Rabbi Elozor ben Yehuda of Worms died in the year 4998 (1238) and was laid to rest in the old Jewish cemetery in Worms.