Isamar Rosenbaum
Rabbi Issamar Rosenbaum (1886-1973) was a Hasidic Rebbe, and the Grandfather of the Extended Hasidic dynasty of Nadvorna and Kretshniff. He was the son of Rabbi Meyer Rosenbaum of Kretshniff, Who in turn was a son of Rabbi Mordechai of Nadvorna.
Issamar Rosenbaum became a Rebbe at the Age of Sixteen, and at his fathers behest, moved to Chernowitz to become a Chassidic Rebbe. In the Nadvorna Dynasty, All Children of the Rebbes open their own chassidic courts, even during their fathers lifetime. His wife, Rebbitzen Malka, was the daughter of Rebbe Usher Yeshaya Rubin of Kolbasov, Poland.
His family was the only chassidic family of grand rabbis known to have all survived the Nazi camps with the whole family intact.
Six Years before his death, in 1967, 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 was known as the Admor Hazaken MiNadvorna, or "Elder Rebbe of Nadvorna".
He died at the age of 86 in 1973.
All his sons and sons in law, were Chassidic Grand Rebbes.
The sole exception, His son Chief Rabbi Meyer Rosenbaum was the Chief Rabbi of Cuba, and a Prolific Author of Scholarly Works.