The Chiddushei HaRim, (Rebbi Yitzchok Meir), was one of the most important disciples of Rebbi Simcha Bunem of Pryschicha and then the fiery R' Menachem Mendel of Kotzk. At the insistence of the Chassidim, the RIM became leader after the death of the Kotzker. At the first Chassidic gathering over which he presided he declared, "Reb Simchah Bunem led with love, and R' Menachem Mendel with fear. I will lead with Torah!"

He succeeded in establishing a precedent of excellence in Torah study which is still a hallmark of the Gerrer Chassidim today.

His grandson, R' Yehuda Leib, known as the Sfas Emes, became Gerrer Rebbe after his grandfather.