Rabbi Yoel Teitelbaum began his rabbinic career in Krooly, a small town in Hungary. In 1929, the Rav of the Orthodox community in Satmar, a larger and more prestigious community, passed away, and Rabbi Teitelbaum was invited for a Shabbos tryout. The Rav displayed exceptional knowledge of Talmud, far above the prevailing image of a Chassidic rabbi, who was expected to be more of an expert in Kabbalah and prayer. He was retained by the community, which prospered under his leadership, and began attracting students to its yeshiva from all over Hungary.
As the War approached, the Satmarer Rav was smuggled out of harms way, first into Switzerland, where he remained throughout the War, and afterwards in 1946, into Israel. On a fund-raising mission to the United States, he met many people from his former community who urged him to stay in America and help them recover from the trauma of the War. Rabbi Teitelbaums decision to stay in America was historic, in that it set in place the foundation for the growth of the Satmar community. After only a short time, the transplanted Yetiv Lev Congregation emerged upon American soil, with Rabbi Yoel Teitelbaum at the helm.
In 1948, he drew worldwide attention when he became the only Jewish leader to denounce the newly founded Jewish state. He based his Anti-Zionist position on a gemara in Ketubot 111a, that derives from the triple mention in Shir HaShirim of the verse, I have bound you in oath, O daughters of Jerusalem, that HaShem bound the Jewish People and the nations of the world with three oaths:
1. shelo yaalu bachoma that the Jews should not forcibly breach the wall, and enter Eretz Yisrael
2. that the Jews should not rebel against the nations of the world
3. that the nations of the world should not oppress the Jewish People excessively during the Exile
The gemara concludes with the threat that if the Jews would violate these oaths, HaShem would bring upon them great harm and physical destruction. Rabbi Teitelbaum claimed that the Zionist movement had brought the Holocaust upon the Jewish People by violating the oaths incumbent upon them.
(Two of the arguments raised against the above are that by the Balfour Declaration the nations of the world gave permission to the Jews to return to Israel. Another is that the oaths would apply to the Jewish People only if the nations of the world did not excessively mistreat them during the Galut. Centuries of massacre and pogrom certainly testify otherwise as to the behavior of the nations of the world. If the nations have violated their oath, the oaths upon the Jewish People are null and void.)
In the 1950s, the Satmar community continued to blossom. Williamsburg became the scene of many inspiring Chassidic gatherings and public tefilos, such as would occur annually on Hoshanah Rabbah, when the Satmar synagogue was a sea of lulavim and esrogim.
By the 1960s, the Satmar community in Brooklyn had grown rapidly and the rebbe had gained many new adherents from immigration to the United States, and his opinions and blessings were sought by thousands.
In the 1970s, the rebbe bought land in Monroe, NY, and founded Kiryas Yoel, where a large branch of the Satmar community now lives.
Tens of thousands of his Hasidim attended his funeral in Kiryat Yoel. None of his children survived him, as all three of his daughters passed away during his lifetime. The Satmar community grieved at the tremendous loss of their rebbe, who had led his followers according to uncompromising principles, in which he deeply believed.
Sources: Orthodox Union