|Full name||Issamar Rosenbaum|
|Buried||Mount of Olives|
|Children||Rabbi Chaim Mordechai Rosenbaum (1903-1976)
Yesochor Ber Rosenbaum (1905-1981)
Rabbi Yitzchok Isaac Rosenbaum (1908-2000)
Rabbi Meir Rosenbaum
Rabbi Asher Yeshaya Rosenbaum
Rebbetzin Isaacson (wife of Rabbi Meir Isaacson)
Rebbetzin Leifer (wife of Rabbi Avrohom Aba Leifer)Rebbetzin Rachel Shapiro (1902 - June 30, 2007)
Isamar Rosenbaum (1886–1973) was a Hasidic rebbe of the Hasidic dynasties of Nadvorna and Kretshnif. 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).
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. In the Nadvorna dynasty, all children of the rebbes open their own chasidic courts, even during their fathers' lifetime. His wife, Malka, was the daughter of Rebbe Usher Yeshaya Rubin of Kolbuszowa, Galicia.
His family was the only chasidic family of grand rabbis known to have all survived the Nazi camps with the whole family intact.
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.
All his sons and sons-in-law, were chasidic rebbes, with the sole exception of his son Rabbi Meyer Rosenbaum, who was the Chief Rabbi of Cuba and Mexico, and a prolific author of scholarly works, including Torah LeOhr Hatekufah.
- Tannenbaum, Rabbi Gershon (Jul 11, 2007). "Kechina Rebbetzin Is Niftar At 105". The Jewish Press. Retrieved July 27, 2011.
- Tannenbaum, Rabbi Gershon (Mar 23, 2011). "Tosher Chassunah". The Jewish Press. Archived from the original on September 15, 2011. Retrieved July 20, 2011. Cite uses deprecated parameter
Rabbi Meyer Rosenbaum of Kretchniff
| Rebbe of Nadvorna
Grand Rabbi Chaim Mordechai of Nadvorna
Grand Rabbi Yesochor Ber of Strozhnitz
Grand Rabbi Yitzchok Isaac of Zutshka
Grand Rabbi Asher Yeshaya of Nadvorna-Chadera