Isamar Rosenbaum was a Hasidic rebbe of the Hasidic dynasties of Nadvorna and Kretshnif.
Background
He was the son of Rabbi Meyer Rosenbaum (1852 - June 29 1908) of Kretshniff, who in turn was a son of Rabbi Mordechai of Nadvorna (1824–1894). Isamar Rosenbaum became a rebbe at the age of fifteen and, at his father"s behest, moved to Czernowitz where he served as a chasidic rebbe.
Career
His family was the only chasidic family of grand rabbis known to have all survived the Nazi camps with the whole family intact. In 1970, three years before his death, he moved from the Washington Heights neighborhood of Manhattan to Yad Eliyahu in Tel Aviv, Israel. At the time of his death, he was one of the longest living chassidic rebbes in history.
He was known as the Admor Hazaken miNadvorna, or "Elder Rebbe of Nadvorna".
He died at the age of 86 in 1973 and was buried on the Mount of Olives.