Nachman was born 1928 in Berlin Germany, to Yoseph and Sarah nee Rechtsstaffen, natives of Poland who immigrated to Germany. He was the middle child between Yitzhak and Baruch in the observant, Zionist household. His father worked in the furniture trade and was Beitar group’s commander in Berlin.  Nachman’s family immigrated to the Land of Israel in spring  1935; his father worked in a Volvo garage and continued work in the Revisionist Party until he passed away 1983. He served as the chairman of the National Workers Union Tel-Aviv, was a member of its National Active Committee and the National Healthcare Organisation. He was also a Tel Aviv Council  member. His three sons  joined Etzel; eldest Yitzhak, became mayor of Bat-Yam. Nachman studied at   the Tachkemoni and Bilu schools, and was influenced by the Lehi publications, “Hama’as” and  “Principles of Revival”. He moved from Etzel to Lehi 1944, recruited by Yosske Vilner. His original name, Norbert Israel, was Hebraized to Nachman. He used Israel as  nom-de-guerre. Nachman was involved pasting-up info-bulletins and distribution in Gadera,  often confronting Hagannah members. He worked in Operations. He participated laying mines near Sirkin airport, and in  the Food-Control Service Building operation. He stood guard while the break-in attempt into Barclay’s Bank Tel-Aviv took place. In June 1946, following the Haifa Railways Workshops operation, he was arrested after a night out in Haifa with eight friends. Imprisoned in Latrun until beginning 1948, then transferred to Atlit, he was released  beginning of May. July 1948 he joined the IDF, Transportation Branch, was transferred to the Air Force and served  until end 1950. Due to his past, he was refused an El-Al job, and  worked in  B.O.A.C Airlines until 1972,except during 1954-1963, when the company closed. He worked as driver and eventually, high ranking clerk. During the period in-between he worked diamond polishing, a profession he acquired 1944 -1946. From 1972 until retirement 1990, he administrated a large diamond polishing factory.

December 1951 he married Henya Dassau,  childhood friend and fellow Lehi member. They had three children Raya, Yair, and Orit, plus eight grandchildren.