Ya’acov was born on April 7,1924 in Tsaberban Hungary. His mother Miriam, née Gutman, and father Shlomo were religious people who made a living managing a restaurant in the city. They made aliya with their five children when Ya’acov was nine. The family settled in Tel Aviv and his father opened a kosher restaurant on Shenkin Street. Ya’acov studied in a Heder and at ‘Tahkemoni’ elementary school. He continued his studies at the technical school attached to ‘Herzliya High-School’. He joined Beitar at a young age, and later Etzel. After the split he joined Lehi. His noms-de-guerre were Hasini and Amos.

Ya’acov’s underground activities focused on technical aspects. Due to his knowledge and expertise, he was assigned to the Technical Department,   inventing  various types of things like doors and secret storerooms, highly useful for the underground. Following the UN Partition Resolution and the riots which erupted before  establishment of the State, he participated in the battles against the Arab Gangs, and the British in Jerusalem. He took part in preparing an exploding car, which he also drove to Jerusalem during the Siege. He transported supplies and weapons in Jeeps through the Burma Road. He fought upon the ‘The Rooftop of Death’ by the walls of Jerusalem, excelling as a sniper.

After the Lehi Center decision to join the IDF, Ya’acov came down from Jerusalem, under a false identity and enlisted with his comrades in the 8th Brigade, serving as a Technical Sergeant in the 82nd Battalion’s Headquarters. He participated in all the 82nd’s battles, including the ‘Dani’, ‘Ayin’, and  ‘Uvda’ operations. During his service in the reserves, he took part in ‘Operation Kadesh’, in the Six Day War, and the Yom- Kippur War. Ya’acov married Bella Weizfeld, a Lehi member (Ruth). The couple had two children and five grandchildren. After the establishment of the State he obtained a license to run a  garage and was a partner in the ‘Rama Garage’ in  Ashkelon.

Ya’acov passed away onJune 13,1987 and was buried in the Lehi section of Holon cemetery.