Yaakov was born on Breslau, Germany, in November 1925, to Mordechai and Mina, to a traditional and religious family. They made aliyah in 1936, settling in Tel Aviv.
Yaakov studied in a religious elementary school. He skipped two grades, and at age fourteen, he was already a sophomore in Moriah Gymnasium. He joined Brit Hashmona’im. He loved natured and organized hikes by foot and by car.
Though his parents disapproved, he attended Yeshivat Hebron in Jerusalem, where he demonstrated himself to be a genius and a dedicated student of Torah. He also was accepted to Hebrew University, with a scholarship — a rare achievement in those days. He focused on world and Jewish philosophy, Kabbala and history. However, he ended up being summoned to the office of the rosh yeshiva when he was seen with a history book, and he was interrogated about it. Yaakov was insulted, so he left Yeshivat Hebron for Yeshivat Mercaz HaRav of Rabbi Kook. This institution was for more nationalist and in keeping with his worldview. The rosh yeshiva, Rabbi Yaakov Moshe Charlap, and his staff were very welcoming and supportive. He continued his activities in Brit Hashmona’im and was recruited to Lehi.
In Lehi, he participated in ongoing operations, firearms training, dissemination of promotional materials, putting up posters and ideological lectures. His room was a meeting-place for underground members, and there was an arms cache dug under his bed. He barely could make ends meet by giving lessons, but he still tried his best to help his comrades. At age nineteen, he was ordained as a rabbi by Yeshivat Mercaz HaRav. However, he did not intend to use this degree professionally, and he never used his title to lord over anyone.
One day in 1946, the CID came to his room, found propaganda and arrested him. Luckily, they did not discover the arms cache. He was detained in Latrun, tried, convicted and sentenced to two years in Jerusalem Central Prison. He continued his studies while in prison, organizing study groups in history, philosophy and Talmud. After the Partition Plan was announced, many of the prisoners were transferred to the detention camp in Atlit, Yaakov among them. Once he arrived, he immediately began planning an escape. He and his comrades began digging a tunnel and planning their escape via the supply route, et cetera. However, May 1948 came and the State was established. They were then freed.
Yaakov immediately enlisted in the IDF. He was offered a chaplaincy position, but he wanted to serve in a combat unit. He was sent to training maneuvers at Kafr ‘Ana (biblical Ono, now part of Or Yehuda).
While the ceasefire was in effect on June 11,1948 Yaakov’s until was suddenly attacked by the enemy. Yaakov was the only who could operate the Spandau submachine gun, and as he ran from one position to another with it, he was struck in the forehead by a bullet and killed instantly. He was only 22.
The papers, which wrote of his heroism, called him “The Genius of Hebron.” He was buried in the Nahalat Yitzhak Military Cemetery.