Radbaz—Rabbi David ibn Abi Zimra רדב"ז — רבי דוד בן שלמה אבן אבי זמרא

Born in Spain in 1479 to a wealthy family. After the expulsion he found himself in Safed—at the age of thirteen. He studied with Rabbi Joseph Saragossi, who had fled Spain in that same 1492.

The Land of Israel was then in want, and before 1513 he moved to Egypt. After the Turkish conquest of 1517 he stood at the head of Egyptian Jewry—judge, head of the yeshiva and administrator of charity; all honorary posts, without salary: he was a man of means and would not take pay.

Two of his acts are particularly remembered. First: he abolished in Egypt the centuries-old custom of dating documents by the Seleucid era—the 'era of contracts'—and moved them to dating from the Creation. Second: a question came to him about the Ethiopian Jews, and he answered that they are Jews. Four hundred years later, when their immigration was being decided, he was cited.

His responsa run to seven parts, and questions came to him from everywhere. His method was strict: he collated manuscripts, compared variant readings, traced things to their source. A kabbalist—but where kabbalah diverged from the Talmud he put the Talmud first.

At the end of his life he returned to the Land of Israel and died at Safed in 1573. Rabbi Bezalel Ashkenazi studied with him; tradition counts the Ari too among his students.