Hornosteipel (or Hornisteipol[1]) is the name of a Hasidic dynasty founded by Rebbe Yaakov Yisroel Twerski.
It is a branch of the Chernobyl and Anipoli dynasties dating back to the 19th century.
Rebbe Mordechai's father, Rebbe Menachem Nachum Twersky of Chernobyl (author of Meor Einayim and founder of The Chernobyl Hasidic dynasty), was a disciple of the Baal Shem Tov, the founder of Hasidism.
The main bases of Hornosteipel Hasidim are in Midwood ("Flatbush"), Milwaukee, and Beitar Illit.
There are also communities with direct ties to Hornosteipel in Chicago, Toronto, Baltimore, and Beit Shemesh, Israel.