Yaacov was born 1911 in a Besserabian town to Naftali, a forester, and Rachel,  who had nine children. Descendants of a religious family, his maternal grandfather, Chayim-Hassin, was Chief Rabbi of the Hatin region.  During the Bolshevik Revolution his parents with their children fled to Bessarabia (under Romanian rule) and settled there. Yaacov studied at a Hebrew school, joined the Beitar youth movement and was of its first most active members.

He became commander, instructor, and organizer of camps. He made aliyah in 1930, stealing through the Syrian border disguised as a shepherd. In Eretz Yisrael he joined Beitar labor groups at Rosh-Pina and Kfar-Saba  becoming a group leader. During the Arlozorov trial in 1933 he was falsely accused of “planning the murder”. He returned to Bessarabia 1936 for a family visit, met Zipora Lerner and they married. On 1937, the couple arrived in Eretz Yisrael and started their home in Tel Aviv.  Yaacov chose  to be a construction worker because, he felt he’d come in order to build Eretz-Yisrael, not to be a paper- pusher. He also worked in agriculture, guarding orchards and paving roads. He was an Etzel member; after the split he joined Lehi. He participated in the big demonstration protesting the White Paper in 1939, and took down the British flag from the Immigration Office at the Tel Aviv museum. Often imprisoned by the British, he sat in Akko, Mizra and Latrun prisons.

He was released, after intervention of family and authorities. He then worked at the National Workers Union managing the ‘Amal Fund’. Following establishment of the State he managed the Netanya ‘Halva’ah Vechisachon’ Bank.  His two sons, Yehonatan and David, whom he educated in the spirit of nationalist-Zionism, were born in Netanya. They both served as doctors, in the Paratroopers Brigade and in ‘Sayeret- Matkal’. Yaacov and Zipora had seven grandchildren.

Yaacov passed away on March 29,1990, and was buried in the Netanya cemetery.