Approximately one thousand years ago, there lived a great Rabbi named Rabbenu Gershom, who was called "Me’or Ha’gola" – "luminary of the Diaspora" – because of his profound influence upon the Jewish People. Rabbenu Gershom issued a number of edicts that were embraced by much of the Jewish world. Rashi (Rabbenu Shlomo Yishaki, Troyes, France, 1040-1105) writes in one place that all Jews are considered students of Rabbenu Gershom, and are thus bound by his edicts, and the Rosh (Rabbenu Asher Ben Yehiel, 1250-1327) similarly writes that Rabbenu Gershom’s edicts are to be treated as though they had been given to us at Mount Sinai.
One of Rabbenu Gershom’s most famous Takanot (enactments) was the prohibition against marrying more than one wife. According to Torah law, there is no restriction on the number of wives that one may have, the only exception being that a king may not marry more eighteen wives (and that the Gemara advises all people not to have more than four wives, even though this is permissible). Rabbenu Gershom, however, enacted a prohibition against having more than one wife.
Different reasons have been given for this edict. The simplest explanation is that Rabbenu Gershom issued this enactment for the sake of ensuring Shalom Bayit (peace in the home). Maintaining peace in the home can be challenging even when one has only wife, and it quite obviously would be far more difficult when there are two wives, a situation that naturally gives rise to jealousy, rivalry and competition. The Ba’al Ha’turim (Rabbenu Yaakob Ben Asher, 1269-1343) finds an allusion to this concept in the verse in Sefer Shemuel I (1:2) which says of Elkana (Shemuel’s father), "Ve’lo Sheteh Nashim" – "He had two wives." The only other time in Tanach where the word "Ve’lo" ("Vav," "Lamed," "Vav") appears is in the verse in Tehillim (7:14) which states, "Ve’lo Hechin Keleh Mavet" – "He prepared for himself lethal weapons." The Ba’al Ha’turim comments that the connection between these two verses lies in the fact that one who marries two wives in effect prepares "lethal weapons," as this arrangement poses the real danger of bitter conflict.
Others explain that if a man marries more than one wife, it would be very difficult for him to properly support them both and meet his various obligations to both, and so Rabbenu Gershom issued this enactment forbidding marrying more than one woman.
Yet another explanation is that this enactment should be viewed in conjunction with a different edict issued by Rabbenu Gershom – that a husband cannot divorce his wife against her will. According to Torah law, a husband is able to throw a Get into his wife’s property and thereby divorce her, even though she does not want to be divorced. Whereas Kiddushin (betrothal) does not take effect without the wife’s consent, divorce, on the level of Torah law, does. Rabbenu Gershom, however, enacted that one may not divorce his wife unless she consents. It has thus been suggested that Rabbenu Gershom issued the ban against marrying more than wife because otherwise, if a man wants to divorce his wife and she refuses, he can just go ahead and marry somebody else. The enactment forbidding marrying more than wife was necessary in order to enforce the enactment forbidding divorcing one’s wife without her consent.
The Shulhan Aruch (Eben Ha’ezer, 1) writes that Rabbenu Gershom enacted that this prohibition should remain in effect until the year 5000 (1240 CE). The Pit’heh Teshuba (commentary to the Shulhan Aruch) explains that Rabbenu Gershom limited his enactment in this fashion in order to avoid violating the prohibition of "Bal Tosif" – adding onto the Torah. If he would have issued this edict to apply for all time, this would have constituted an addition to Torah law, which would violate "Bal Tosif." He therefore placed a limit on his edict, that it should apply only until the year 5000. Nevertheless, it generally assumed that the Jewish People agreed to extend this prohibition beyond the year 5000.
The Shulhan Aruch rules that Rabbenu Gershom’s edict does not apply in the case of Yibum – where a married man’s brother dies without children, such that the surviving brother has a Misva to marry the widow. In such a case, the brother may marry the widow even though he is already married to somebody else, so he can fulfill the Misva of Yibum. The commentators explain that in this situation, it is as though G-d Himself gives the man a second wife, and Rabbenu Gershom’s edict cannot override the will of G-d, who has determined that the brother should marry the widow.
The Rama (Rav Moshe Isserles of Cracow, 1530-1572) addresses the case of a man who has been unable to produce children after ten years of marriage, and wishes to marry a second wife so he can procreate. According to the first opinion brought by the Rama, just as Halacha permits marrying a second wife for the sake of fulfilling the Misva of Yibum, one is likewise allowed to marry a second wife for the sake of the Misva of procreation. The second view, however, that of Mahari Mintz (Italy, 15th century), maintains that although an exception is made for Yibum, an exception is not made in the case of a man whose first wife cannot bear children. The Rama presents these two views in a style of "Stam Va’yesh" – plainly mentioning the first opinion, allowing marrying a second wife in this case, and then adding, "Ve’yesh Holkin" – "and some disagree." Hacham Ovadia Yosef (Yabia Omer, vol. 7) cites the Peri Megadim (Rav Yosef Teomim, 1727-1793) as stating that when the Rama presents two views in this style, he sides with the first view. Just as when the Shulhan Aruch presents two views in this fashion, we follow the rule of "Setam Va’yesh Halacha Ki’stam" – the Shulhan Aruch sides with the first opinion, this is true of the Rama’s rulings, as well. Accordingly, Hacham Ovadia writes that if one has been married for ten years and was unable to produce children, he would receive permission from Bet Din to marry a second wife. However, the Bet Din would allow this dispensation only if it can determine that the husband can support both wives, and that the wives would live in separate homes.
Hacham Ovadia disagrees in this regard with Rav Haim Palachi (Turkey, 1788-1868), who was brought a case of a couple that was married for twenty years without children, and the wife agreed to allow her husband marry another woman. Rav Haim Palachi concluded that he did not feel authorized to permit the man to marry another woman, despite four different uncertainties regarding the applicability of Rabbenu Gershom’s edict. First, it is not entirely clear that Rabbenu Gershom’s Takanot were accepted by Sephardic Jews. The Rashba (Rav Shlomo Ben Aderet of Barcelona, Spain, 1235-1310) writes that in Spain and some other regions, Rabbenu Gershom’s edicts were not accepted, and this is the view also of Maharam Alshakar (1466-1542). Additionally, as mentioned, the edict was enacted to apply only until the year 5000, and one might argue that it is not actually binding beyond that point. Thirdly, it is possible that the edict allows marrying a second wife for the sake of the Misva of procreation. And, it is possible that the edict does not apply in a case where the first wife allows her husband to marry a second wife. Nevertheless, despite all these factors, Rav Haim Palachi had such reverence for Rabbenu Gershom that he could not bring himself to allow this man to marry another woman. It should be noted that the word "Herem" ("ban," or "edict") in Gematria equals 248, the number of organs in a person’s body, emphasizing the severity of a "Herem," the violation of which can affect one’s entire body. Given the severity of a "Herem," Rav Haim Palachi did not feel comfortable permitting the man to marry another woman in this case.
Hacham Ovadia, however, writes about Rav Haim Palachi’s ruling, "Hifriz Al Ha’midda" – it was too extreme, as all these factors should certainly suffice to permit the man to marry a second wife in this case.
Of course, many countries have civil laws forbidding polygamy, and so this ruling is, in most cases, theoretical.
We might learn from this discussion, though, the importance of Shalom Bayit, that every couple must work hard to build a peaceful, happy relationship. Rabbenu Gershom enacted this prohibition in order to avoid strife in the home – teaching us that we must all endeavor to maintain peace and harmony in our homes.