Years: 1787–1859
Primary city: Kock
Rabbi Menachem Mendel Morgenstern was the first Rebbe of the Kotsk dynasty, a significant figure in Polish Chasidut. He was known for his rigorous demand for absolute truth and his rejection of superficiality. Though he left no written works, his teachings were preserved by his disciples in collections such as Emes ve-Emunah.