Rav Aharon was the son of Rav Kalonymous Kalman Epstein of Cracow, mechaber of Maor Voshemesh, and the son-in-law of Rav Yisrael Horowitz, who was the son of the Chozeh of Lublin.
After his father’s petira in 5583, he opened a Bais Medrash in Cracow but refused to serve as a Chassidishe Rebbe. Eventually he accepted upon himself the authority of Rav Shlomo HaKohen of Radomsk, mechaber of Tiferes Shlomo, and was considered among his greatest talmidim. Rav Shlomo himself testified that he was oron nosei es nos’ov – “‘Aharon’ carried/supported those who carried/supported him!”
He was well beloved by the residents and citizens of Cracow and was the first signatory on the appointment letter for Rav Shimon Sofer as the chief Rav.
He lived a long life but left no children. His Bais Medrash and namesake stood until the days of the Holocaust.
(See Rav Zevin’s Sippurei Chassidim Torah 217.)
