Kashau (קאשוי) (also often spelled, as pronounced by most Ashkenazic Jews, Kasho) is a hasidic dynasty led today by Grand Rabbi Eleizer Chaim Blum. Kashau institutions are presently located in Williamsburg, Monsey, and Bedford Hills, New York. Followers of the Kashau Rebbe live in other Jewish centers around the world. The Rebbe's advice is also sought by many Jews who are not hasidim of Kasho and who do not necessarily live according to the holy takannos of Kashau. The Rebbe has authored several books of Hasidic tales, and is known as a pious leader, a brilliant thinker, and a skilled orator.
The Kashau Rebbe, R’ Rafuel Blum (1911–2005), was a talmid from R’ Shaul Brach, zt"l (1865–1940), Rav, Rosh Av Beis Din, and Rosh Yeshiva of Kashau, and formerly of Magendorf and of Kruleh. R’ Rafuel Blum learned in R Shaul Brach's yeshiva for twenty-five zmanim thereby making R’ Shaul Brach his Rebbe Muvhak and role model. He constantly sought the advice of his holy Rav. Before World War II, the Rebbe led a yeshiva in Mihalowitz. The Rebbe was liberated from the Nazis on January 18, 1945 to the city of Arad in Romania. In the summer of 1945, the Rebbe returned to Kashau. The Rebbe was influential in establishing the halachic status of survivors of the war, freeing them to remarry after determining that their spouses had been killed.
In 1948 the Rebbe arrived in Brooklyn, New York and began the work of transferring his yeshiva from Kashau. Shortly afterwards, the Rebbe was appointed rosh yeshiva of the Tzelemer Yeshiva Arugas Habosem. At that time, the Rebbe founded Kehillas Kashau in the Williamsburg section of Brooklyn. In 1962 an unsuccessful attempt was made to establish the kehillah in Morris County, New Jersey. Eventually the Rebbe started yeshivos and a secluded village for Kashau hasidim in the forests of Westchester County, outside Bedford Hills. The village is known as Kiryas Kashau today. R' Rafuel's piety and brilliance were widely acknowledged. Talmidim from the Rebbe's yeshivos are an influential presence in many branches of Hungarian hasidus today.
Kashau is most associated with Kiryas Kashau, although many hasidim live in Williamsburg and Monsey, New York. R' Rafuel's oldest son, Eleizer Chaim, the current Kashau Rebbe, resides in Monsey.
The Kashau hasidus is relatively small and considered extremely devout, even among other hasidic groups. The hasidus is known to be quiet and peaceful, despite their strict and sometimes controversial views on kashrus, zionism, tznius, and education.
The Rebbe was an influential advocate of the traditional practice of metzitza b'peh and its legal status in New York City.