Following the death of his father-in-law right before the Purim holiday in 2005,[3] a dispute arose as to who should be the Grand Rebbe of the then 120,000 Bobov Hasidim worldwide.[1] Some began to follow Ben Zion Aryeh Leibish Halberstam, his father-in-law's half-brother,[1] while others followed the older (by one year) Unger, who had by then already ensconced himself firmly within the community.[1] Unger could not challenge his own father for leadership of Dombrov, which anyway was not as substantial a dynasty as Bobov.[4] The matter of succession was brought before a beth din (religious court) in 2007, which ruled that Halberstam would be declared Rebbe of Bobov (אדמו"ר מבאבוב) with its headquarters on 48th Street in Borough Park, Brooklyn,[5] while Unger would be Rebbe of Bobov-45 (אדמו"ר מבאבוב-45), located on 45th Street.[5][6]
