After his father-in-law Grand Rabbi Naftali Halberstam passed away, some chose to follow Rabbi Mordche Duvid Unger, while most followers chose to follow his brother Rabbi Ben Zion Halberstam, half-brother of Grand Rabbi Naftali Halberstam.
After his father-in-law Grand Rabbi Naftali Halberstam passed away, Bobov split in two. Many chose to follow Rabbi Mordche Duvid Unger, while many chose to follow Rabbi Ben Zion Halberstam, half-brother of Grand Rabbi Naftali Halberstam.