Ya’acov was born on March 9, 1931 in Neve Tsedek, Tel-Aviv to Shabtai and Margalit, née Amsalem, an eighth generation Israeli. Ya’acov and his seven brothers and sisters were raised in a warm household and were educated in Zionism and love of the nation and homeland. He studied at the Alliance school and graduated form the school in Neve Tsedek. He was a member of the Tel Aviv Zebulun tribe Sea Scouts and took up boxing.
In 1946 he joined Lehi and was integrated into the youth department and was mainly involved in putting up posters, distributing campaign material, communications and surveillances. He also obtained names of candidates for recruitment. Between 1947 and 1948 he worked for customs and ship merchants in Jaffa port. Ya’acov was the youngest employee and dealt with mailing and coordination between the offices of the company in Tel Aviv and in Jaffa. As part of his work requirements, he was given entrance passes to facilities under the supervision of the British Police (such as Haifa and Jaffa ports and the railroad station at Mikve Israel Street in Tel Aviv). This type of certificates, approved by the British CID, was distributed to people who were involved in collecting imports from customs. After they were copied and duplicated, and with the addition of other papers, they enabled Lehi members to enter Jaffa port with a truck and detonate a bomb in the Saraya building where the Arab gangs’ headquarters were situated..
After the establishment of the State he joined the IDF and served in the Armored Corps as a regular and reserve soldier. After his discharge he joined Eged and worked in diverse positions. In 1977 he retired and started working in land leasing. On December 17, 1957 he married Ruth, née Gormens. They had three children, Anat, Erez and Alon and five grandchildren. In 1979 the family moved to Los Angeles to seek its fortune. They returned to Israel in 1992 and settled in Herzliya.
Ya’acov was an open loving man, an ardent Zionist, and always inspired good cheer and confidence in his comrades in arms. Many were surprised to discover that Ya’acov had been an underground fighter before the establishment of the State. He kept in touch with many Lehi members and participated in its events and conferences.
In January 1998 he suffered a minor stroke, but recovered completely. With the help of his family and friends he returned to full activity. But on September 17, 1998, the 26th of Elul 5758 his heart suddenly gave out and he passed away during a holiday in Germany at the age of 67. He was buried in the Lehi section of the cemetery in Herzliya.