The Takkanot of Rabbeinu Gershom

A takkanah is a rabbinic enactment: not an interpretation of scripture but a new rule, made by a competent authority for the good order of the community. The two that made Gershom's name concern marriage.

The first forbids a man to be married to more than one woman at a time. Biblical and talmudic law permit polygyny, and Jewish communities in the Islamic world practised it into the modern period. The Rhineland ordinance closed it in Ashkenaz, and the closure held so firmly that within a few generations it was treated as though it had always been the law.

The second forbids a husband to divorce his wife against her will. Under talmudic law a divorce is effected by the husband delivering a bill of divorce, and the wife's consent is not required. The takkanah supplies it. Together the two ordinances gave a Jewish wife in northern Europe a security her contemporaries elsewhere did not have, and Avraham Grossman has argued that this is part of a wider improvement in the position of Ashkenazi women in the same period.

The third forbids opening and reading a letter addressed to another person, an early and often cited rule of correspondence privacy in a society whose commerce ran on letters carried by third parties. The fourth forbids reminding a Jew who was forcibly baptised, and has returned, of what he did under compulsion.

Two things about these ordinances are less settled than their status suggests.

The first is authorship. Gershom ben Judah of Mainz, called the Light of the Exile, died in about 1028, and his standing was such that later enactments of the Rhineland academies were attributed to him as a matter of course. Historians working from the manuscript record, Louis Finkelstein among the earliest, have argued that several of the ordinances that travel under his name were enacted by synods after his death and gathered under his authority afterwards. The core is generally accepted as his; the edges are not.

The second is duration. A tradition reported in later authorities holds that the ordinances were enacted only until the end of the fifth millennium, that is until the year 1240 of the common era. Nobody acted on that expiry. The rules were reaffirmed, treated as accepted custom, and in the case of the monogamy rule reinforced by the sanction of a ban against anyone who breached it, so the question of formal expiry never became practical.

Their geographical reach was always limited. The ordinances bound Ashkenaz, and Sephardi and Mizrahi authorities did not adopt the monogamy rule on the same footing, though most communities restricted polygyny by other means such as a clause in the marriage contract. The practical divergence was closed in Israel in 1950, when the Chief Rabbinate applied a monogamy rule to all communities under its authority.