Sunday 24 February 2019


Rabbeinu Gershom's commentary to the Talmudic tractate of Bava Batra.

Rabbeinu Gershom ben Yehudah (960-1040), also known as Me’or haGolah (The Light of the Exile) was born in Metz (France) and later moved to Mainz in Germany where he established his famous teaching academy.

Three of his students were later to become teachers of Rashi[1] - who was born around the time of Rabbeinu Gershom’s passing[2] - and who, at the age of eighteen, travelled to Mainz to study in that very Yeshiva established by Rabbeinu Gershom.

The grave of  R. Yaakov ben Yakar in Mainz, Germany - student of  Rabbeinu Gershom and the teacher of Rashi.

Rabbeinu Gershom was a great scholar and is said to have revised the text of the Mishna and Talmud. Also, a commentary on nine sections of the Talmud is ascribed to him.[3]

Today, one can still see his tombstone in the ancient cemetery in Mainz.

In this article, we will look at some of the innovations he introduced to Judaism around the year 1000, focussing particularly on his stance against polygamy.


Rabbeinu Gershom’s son converted to Christianity. 

This may or may not have been a forced conversion as voluntary conversions were quite common at that time[4]. Later, after the son pre-deceased his father, Rabbeinu Gershom apparently mourned him for fourteen days (seven as per the usual mourning period, and another seven for having converted out of the faith).

This dramatic event, apparently, influenced his decree that someone who had been subjected to baptism could revert back to Judaism without stigma – and would even be permitted to say a blessing over the Torah in a synagogue.

About five hundred years later, this was to become a pressing issue when Conversos and Marranos who had fled the Spanish Inquisition of 1492 began to return to Judaism. Some felt that only a Sanhedrin could absolve them from their apostasy. 

Others would have relied on Rabbeinu Gershom’s more lenient ruling. [For more on the attempt at reestablishing the Sanhedrin see here]


But his takkanah[5] or decree, regarding apostasy, was not his only innovation to Jewish law. He introduced a number of decrees which are regarded as somewhat liberal, modern and moral innovations to Judaism.

For example, he introduced the Cherem haYishuv, where businesses were to be protected from competition within the same area.

He made it illegal to read another’s mail. Typically, mail would contain a seal ‘beChadrag’ (beCherem deRabbeinu Gershom’) warning others, that on the threat of excommunication, this letter was a private communication. This was an insightful innovation, ahead of its time, influencing future privacy laws which we take for granted today.

He made it illegal, under Jewish law, to divorce a woman against her will. Rabbeinu Gershom’s second wife was a widow, and it is said that he had particular empathy for women who had been somewhat neglected and mistreated by society.

In keeping with his empathy for the plight of women, he prohibited polygamy, which until then was still technically permitted under Biblical law. Jacob, for example, had four wives. But Rabbeinu Gershom believed that multiple wives would be unfair on the women and a source of potential strife (as indeed it was in Biblical times).


Let us look at the social milieu during the Talmudic period in the preceding centuries before Rabbeinu Gershom:

According to, during Talmudic times, an interesting dynamic developed: The Halacha followed Rava who ruled that one may take more than one wife on the condition that one is able to support both wives properly.[6] However, the reality was that polygamy was not commonplace during Talmudic times and we rarely find instances of a Talmudic sage taking multiple wives.

A very different view is put forward by Rabbi Professor Yaakov Elman whose research shows that “there is ample evidence that polygamy continued to be practised there [in Talmudic Babylon][7]

There was even the notion of ‘temporary marriages’ which was practised by Rav Nachman and Rav. [See Babylonian Influences on the Babylonian Talmud.]

Interestingly, this was not the case in Eretz Yisrael where polygamy had been virtually eliminated, probably as a result of Jews becoming Roman citizens in 212 CE, and Roman law had outlawed bigamy (- marrying someone while already married to another person).


Clearly, in post-Talmudic times, attitudes towards polygamy began to change:

According to Professor Avraham Grossman of Hebrew University, by the year 1000, polygamy had all but vanished from most Jewish communities. Thus, in effect, Rabbeinu Gershom’s edict was more of rubber-stamping of a newly established social order, rather than an outright innovation.


Another view is taken by R. Simon Eppenstein, who in his century-old article on the topic suggests that although there was no polygamy in Germany in Rabbeinu Gershom’s time, there was nevertheless an influx of Sefardic Jews from Islamic countries who had migrated to Germany. 

According to this, the decree of Rabbeinu Gershom was directed against these immigrants, almost in an attempt to prevent “the daughters of Germany’s monogamous society from becoming second wives to Sefardic Jews.”
Grossman disagrees with Eppenstein and maintains that there was no significant migration to Germany by Sefardic Jews at that time.

To complicate matters, there is a responsum a written by Rambam[9] (1135-1204) more than a century after Rabbeinu Gershom, where he criticises the fact (or impression) that French Jews were of the habit of taking more than one wife. (Northern France and Germany were usually regarded as a single entity).

Either way, the Cairo Geniza documents certainly do show that during the Middle Ages, polygamy was prevalent among the Jews who lived in Islamic countries.


Although the general assumption is that the ban against taking more than one wife is ascribed to Rabbeinu Gershom – there are no records of this ban from any existing French or German sources!

The first written evidence of the ban only appears about a century after Rabbeinu Gershom’s death.

The first person to mention this ban, was R. Eliezer ben Natan who does not even mention Rabbeinu Gershom, but simply refers to it as ‘takanot haKehilot’ or communal bans.


Shulchan Aruch, Even haEzer 1:10 (Large font is R. Yosef Karo who is followed by the Ramo.)

R. YOSEF KARO (1488-1575):

R. Yosef Karo, known as Beit Yosef writes that the decrees of Rabbeinu Gershom expired in the year 1340 (which corresponded to the end of the fifth millennium.)[10] Based on this, he ruled in his Shulchan Aruch that the decrees are no longer in effect.[11]  
He cites the Rashba (1235-1310) that the enactments only applied in specific geographical areas, and the decrees “were not made for all places… The decree did not spread to our borders, and even in Provence and the areas close to France, we have not heard that it has spread. In practice, too, Torah scholars in our vicinity commonly wed more than one wife, and nobody has been concerned for this matter.”

The ban was originally limited only to Germany and the parts of France. However, it soon spread to Poland and European Russia. It was not accepted in Southern France, Spain, Italy, Greece, Turkey, Israel, Africa and Asia.

RAMO (1530-15720:
R. Moshe Isserless, known as Ramo (who wrote notes to the Shulchan Aruch following the Ashkenazi custom) wrote that although technically the decrees may have elapsed, nevertheless, the custom was to still follow them.

MAHARSHAL (1510-1573):

R. Shlomo Luria, known as Maharshal, argues strongly that the decrees are still in effect. This is backed up by the later Pischei Teshuva[12] who writes that this was indeed the consensus of most Rabbis in the period of the Rishonim.


Dr Henry Abramsom suggests that it is possible that since the Church had established monogamy as a societal norm, Rabbeinu Gershom was happy to perpetuate it as well.

This view is borne out by R. Yaakov Emden (1697-1776) who writes that the ban was originally instituted as a result of Christian influence. He writes that the ban was inherently flawed from a Jewish point of view but had Rabbeinu Gershom not made this ban, the Christians may have persecuted the Jews for polygamy:

"In us is fulfilled, due to our many sins, the verse 'and they will be mixed among the nations etc.,' therefore it is proper to eliminate it (the ban on taking more than one wife).

Did they not say that he (Rabbeinu Gershom) only made his ban until the year 5000...

It would have been proper not to have made such a prohibition in the first place because of the prohibition of following in the ways of the nations, but because it didn't require a positive action to comply, and also because of the danger to the Jews who live among the uncircumcised when they marry two wives, Rabbeinu Gershom, light of the exile, needed to make this ban which was not right to make [shelo min hadin]"[13]

VILNA GAON (1720-1797):

Most surprising is the view of the Vilna Gaon who is cited as saying that bringing polygamy back would bring the redemption nearer. He said that removing the ban against polygamy was only one of two things he would interrupt his Torah study for - provided he knew he would be successful in achieving it.[14]

The other matter was to reintroduce the reciting of the Priestly Blessing on a daily basis. As it happened, his students were able to make this part of the custom of Eretz Yisrael.

R. OVADYA YOSEF (1920-2013):

In more recent times, R. Ovadya Yosef writes that Sefaradim follow the abovementioned ruling of R. Yosef Karo - who wrote expressly for Sefaradim in his Shulchan Aruch - and that they consider the decree to be no longer applicable. In his book, Yabia Omer, R. Yosef writes that it is a mistake for non-Ashkenazim to follow Rabbeinu Gershom’s ‘stringency’ which prevents a man to marry more than one wife. 

The law of the State of Israel, however, does not permit polygamy.

R. Yosef cautions that the marriage document must include an explicit stipulation that it is forbidden for the husband to take a second wife. He further mentions that under certain conditions - such as in a case where a Sefardic couple had been married for more than ten years without producing children - then the Israeli Chief Rabbinate should issue a permit to make an exception to Israeli law, and allow the man to take a second wife.[15]


The ban against polygamy was not absolute because there were escape clauses – such as in a case where a wife refuses to accept a divorce for an unreasonably extended period of time. In such a case one may rely upon a Heter Meah Rabbanim, or Permission of a Hundred Rabbis, who agree with a ruling of a Beit Din that such a case merits the expediency of annulling the ban.[16]


In a recent Jerusalem Post article, the Tel Aviv Rabbinical Court ruled that a particular husband who could not locate his wife may marry a second wife. This was pursuant to a request by the husband who was unable to obtain a divorce from his first wife who had emigrated and gone into hiding with her children.

“In light of the fact that the two parties have been separated for six years and the location of the woman is not known and she is hiding from the law enforcement authorities, the rabbinical court believes that she is obligated to accept the divorce,” the court ruled.
“Since there is no possibility at this stage of arranging a divorce, the husband must be allowed to remarry and be given dispensation from the decree of Rabbeinu Gershom.”[17]

[1] Rashi had three teachers, all of whom were students of Rabbeinu Gershom): R. Yaakov ben Yakar whom he referred to as mori haZaken, R. Yitzchak haLevi, referred to as mori haRav haLevi, and R. Yitzchak ben Yehudah, referred to by Rashi as mori Tzedek.
[2] Rabbeinu Gershom passed away at the end of the period of the Gaonim - 1038/40 - and Rashi was born at the beginning of the period of the Rishonim.
[3] For an academic discussion on this issue, see here.
The printers of the Vilna Talmud printed several newly discovered commentaries in the outer margins of their edition. These included some of the most important of the early medieval works. Scholars were sent to European libraries (including that of the Vatican in Rome) in order to copy out these lost treasures of Jewish religious literature. Since none of these commentaries covered the full text of the Talmud, different ones were printed with the individual tractates. The additional commentaries include the following: Rabbeinu Gershom, Rabbeinu Chananel, Shitah Mekubetzet, Tosefot Rid, Tosafot Yeshanim.
[4] According to Dr Henry Abramson, while this may have been a forced conversion, it is not unlikely that it was voluntary as most of the forced conversions began sometime later, well within the 11th century. On the other hand, Jews were expelled from Mainz in 1012, and this might support the notion of a forced conversion.
[5] Known as Cherem deRabbeinu Gershom.
[6] Yevamot 65b.
[7] Babylonian Echoes in a Late Rabbinic Legend, p. 15.
[8] Takanot Rabbenu Gershom - Ban on Polygamy, by Benji Hopper as part of his research for his Masters Course.
[9] Grossman questions the authenticity of this responsum from Rambam and says that even were it to have been authentic, this was only referring to the Jews of France and not to those of Germany. [On the other hand, Northern France and Germany are usually linked together in reference to the Tosafists who were active in the two centuries after Rashi (1038-1105).]
[10] Even haEzer 1.                                                                                                                                                   
[11] Even haEzer 1:10.
[12] Pischei Teshuva 1:19. This Halachik work was written by Tzvi Hirsh Eisenstadt (1815 - 1868).
[13] Shut Sh'ilas Yaavetz vol 2, Siman 15.
[14] Ma’aseh Rav haShalem, p. 276.
[15] Yabia Omer 7:2
[16] The get is deposited with the court and the wife remains married until she takes possession of it.              
[17] Jerusalem Post, 8 Jan 2019.


  1. Excellent article as usual

    One point.

    You write:
    Pischei Teshuva 1:19. This Halachik work was written by R. Yisroel Yisser Isserlin (1390-1460) and it was one of the sources for the later work of R. Moshe Isserle


    Regarding the above:
    Tzvi Hirsh Eisenstadt (1815 - 1868 CE)in Even Hoezer Pischei Teshuva 1:19 says " the decrees are still in effect"

    Not R. Yisroel Yisser Isserlin (1390-1460)

    However Yisroel Yisser Isserlin 1827-1889 wrote Pischei Teshuvah on Orech Chayim

  2. But how could that have been a source for Rama who was born in 1530? Unless there are two books by the same title?

    1. None of the 2 Pischei Teshuva's were of course a source for the earlier Rama. I did not mean to imply that.

  3. Is there a misunderstanding?

    You write:

    "R. Shlomo Luria, known as Maharshal, argues strongly that the decrees are still in effect. This is backed up by the earlier Pischei Teshuva[12] who writes that this was indeed the consensus of most Rabbis in the period of the Rishonim.


    Pischei Teshuva 1:19. This Halachik work was written by R. Yisroel Yisser Isserlin (1390-1460) and it was one of the sources for the later work of R. Moshe Isserless

    I believe this should be amended as follows:

    "R. Shlomo Luria, known as Maharshal, argues strongly that the decrees are still in effect. This is backed up by the LATER Pischei Teshuva[12] who writes that this was indeed the consensus of most Rabbis in the period of the Rishonim.


    Pischei Teshuva 1:19. This Halachik work was written by Tzvi Hirsh Eisenstadt (1815 - 1868 CE).

    R. Yisroel Yisser Isserlin (1390-1460) was no doubt in general a source for Rama, but as far as I know he did not write Pischei Teshuva and from the point of view of your article is not relevant to the decree.

  4. Thank you Gershon. I have amended the text accordingly.

  5. Monogamy is a Christian doctrine. Jews were persecuted, mocked and burnt on the stake for having more than one wife. That is the reason Rabbeinu Gershom decreed his ban. The Jews in Sephardic countries did not have such a problem so they did not accept the ban. The question is of course why did Rabbis Ouziel and Herzog perpetrate the ban in the State of Israel for Jews and not for Arabs (!).