Mordechai Dovid Unger

Mordechai Dovid Unger (, born 1954) is the first Rebbe of Bobov-45. Upon the passing of his father-in-law, Unger was appointed Rebbe of a breakaway group of Bobover Chassidim who wanted to be independent of the fifth and current Bobover Rebbe.

Biography Unger was born to Yaakov Yitzchok Unger of Dombrov. He is the younger son-in-law of Naftali Zvi Halberstam, the fourth Bobover Rebbe.

Following the death of his father-in-law right before the Purim holiday in 2005, a dispute arose as to who should be the Grand Rebbe of the then 120,000 Bobov Hasidim worldwide. While the majority began to follow Ben Zion Aryeh Leibish Halberstam, his father-in-law's half-brother, others followed the older (by one year) Unger, who had by then already ensconced himself firmly within the community. Unger could not challenge his own father for leadership of Dombrov, which anyway was not as substantial a dynasty as Bobov. The matter of succession was brought before a beth din (religious court) in 2007, which ruled that Halberstam would be declared Rebbe of Bobov with its headquarters on 48th Street in Borough Park, Brooklyn, while Unger would be Rebbe of Bobov-45 , located on 49th Street.

Rebbes of Bobov Shlomo Halberstam (1847–1905), grandson of the Sanzer Rebbe, Chaim Halberstam Ben Zion Halberstam (1874–1941) Shlomo Halberstam (1907–2000) Naftali Halberstam (1931–2005) Mordechai Dovid Unger (b. 1954), son-in-law of Naftali Halberstam

Politics Brooklyn Borough President Eric Adams visited Bobov–45 as part of his 2017 re-election campaign.