Menahem Mendel, also known as the Menahem Mendel of Kotzk, was a prominent Hasidic rabbi in the 19th century. He was born in 1787 in Poland and became known for his deep spiritual insights and emphasis on authenticity in religious practice. His teachings often focused on the importance of inner truth and personal connection to God. Menahem Mendel founded the Kotzk Hasidic dynasty in the town of Kotzk, which attracted many followers. He was known for his sharp intellect and sometimes controversial views, which challenged conventional norms within the Hasidic community. He passed away in 1859, leaving a lasting impact on Jewish thought and spirituality.