Hi all!
The Patriarchs and other great men in the Tanakh (what we call what Christians call the "OT") were polygamous, although our Sages tell us that they were exceptions to the general rule and until it was banned, polygamy was very uncommon. Of all the myriad Sages mentioned in the Talmud, ferinstance, none is mentioned as having more than one wife. Jewish law did permit a man to take more than one wife as long as he could support them all equally. But around 1000 CE (what we say instead of "AD"), leading European rabbis pronounced a ban on polygamy, which, as I've said, was never very widespread anyway. This ban was eventually adopted by rabbis in Islamic countries as well, except for Yemen. Polygamy, as rare as it was, was not unknown among the now, all-but-vanished Yemenite Jewish community. Most Yemenite Jews have moved to Israel. While the Israeli Chief Rabbinate has confirmed & reissued the ban on polygamy for all Jews, those Yemenite Jews who came to Israel with more than one wife were not required to divorce all but one. There still are a few elderly polygamous Yemenite Jews still living but as they pass on, the institution will die with them.
I've had Mormon pro-polygamists shriek at me that our rabbis are daring to change God's endorsement of polygamy. We do not believe that He has endorsed polygamy at all; rather, we believe that He has given us the sacred institution of marriage & has authorized our Sages to regulate it. Thus, polygamy is something that we can keep or drop; we've chosen to drop it.
Be well!
ssv