Nachman was born on March 2,1929 in Oman Ukraine, to Rabbi Moshe Gruman, a leading Breslav Hassid, and Breina,  grandaughter of the ‘Maggid of Mezerich’. Nachman was named after Rabbi Nachman of Breslav. In 1934, with Nachman aged five, his parents managed to obtain a Certificate (immigration visa) thanks to Yitzhak Greenboim, and the family made aliya. They settled in a housing hostel in the Old City of Jerusalem. Even in his childhood he proved to be an exceptionally gifted student, at the ‘Mir-Yeshiva’. In 1944, aged  15, he joined Lehi. Like all recruits his age, he pasted info-bulletins, distributed info material, and carried out surveillance. At 17 he joined the Police Force, was assigned to the Prison Service and posted to the Jerusalem Central Prison. As a prison guard he contacted Lehi inmates, helping them in many ways. They called him the ‘redhead policeman’. He delivered secret mail to them and certain necessities. It was he who brought Anshel Spielman the clothes to disguise himself as a cleaner and escape from prison. Nachman was very helpful, especially with the tunnel which was dug out to reach the sewage system, through which several Lehi and Etzel prisoners managed to escape. When their escape was discovered, the British CID suspected Nachman of having helped the escapees. The police appeared at his door ready to arrest him, held a complete search through his apartment but he was gone, forced to remain underground.  After the establishment of the State he joined the IDF’s  8th Brigade along with all his underground friends. He served with Lehi members in the 82nd Battalion,  participating in all the battles which the battalion  fought. Following the War of Independence and his discharge, he left for the US and began working in commerce. Nachman passed away on November 26, 1981.