Years: 1787–1859
Primary city: Kock
Rabbi Menachem Mendel Morgenstern was a Chassidic rebbe in Poland and the founder of the Kotzk Chassidic dynasty. He left no personal writings, as tradition holds he burned his manuscripts, but his teachings were compiled posthumously in works such as Amud haEmet. His teachings and disciples formed the basis for several later Chassidic groups, including Ger and Sochatchov.