Yitzchak was born 1891 in Posnan Germany (today’s Poland), to Dr. Aaron Hepner, a Rabbi in Breslav. He had eight younger sisters. He was already an enthusiastic Zionist while  studying medicine. He served as a doctor in the German Army WWI, and raised a family in Hamburg  with Yocheved (Irma), née Ramer. He established the ‘Mizrahi Youth Movement’ at his hometown, while his wife trained Jewish youths for aliya. In 1932 he took part in the German Maccabi delegation to the first ‘Maccabiya’ in Tel-Aviv, then made aliya with his family, October 1934. They were not accepted by a kibbutz, and settled in the Kerem-Avraham neighborhood, Jerusalem.

Yitzchak joined the Revisionist Movement. His sons, initially in ‘Maccabi-Hatsa’ir’, later joined Beitar.  Before the split he was active in Etzel. Early 1939, he was sent to Belgium with Yermiyahu Halperin to raise money for aliya and re-armament. At the outbreak of WWII, he managed to return to Israel aboard an immigrant ship. During the fight against the foreign occupier, he wholeheartedly assisted  Etzel and Lehi. As surgeon, he treated the wounded from both at his small Jerusalem home-clinic, or anywhere else, anytime, risking self and family. One of his patients was ‘Tall Blond-Dov’.

Dr. Hepner assisted the escapes of Geula Cohen and  Dr. Eldad. Later he organized first-aid courses for the women of Lehi and Etzel. After the demolition of the Jerusalem Railway Station, October 1946, when Meir Feinstein was wounded, Dr. Hepner and all his children were arrested. Following a hunger strike and the Medical Union’s intervention, they were released – except his son Menachem, an Etzel member. Disappointed at the reality of a divided Eretz-Yisrael after the State emerged, he discontinued all public and Party activities. He could not reconcile the gap between the Zionist dream and  Governmental injustice and alienation directed at fighters who’d risked their lives contributing to establishment of the State.

The Hepners had two sons, Menachem and Yaacov, and one daughter Shulamit, (all German-born before the family’s aliya), seven grandchildren plus twenty great-grandchildren. Dr Hepner passed away on December 16, 1973 in Jerusalem, aged 83.