Yaacov was born on July 22,1923 in Lodz Poland, to Reuven Ze’ev, a wealthy merchant, and Pnina. He studied at a Polish-Jewish school. He was a strong healthy athlete, and gifted student. From a young age he aspired to make aliya, joined  Beitar in his youth and enlisted in the Etzel cells, initiated in Poland. At the outbreak of WWII, 1939, he ran away with his friend Baruch Kotlitzki and volunteered for the Polish Army. He took part in the defense of Warsaw, was captured, then escaped from the prisoners train and returned to Lodz.

Yaacov managed to make aliya 1941, and joined the Beitar group and  Etzel in Rosh-Pina. After the Etzel split he joined Lehi, and was expelled from his Beitar group as a result. Dov then came to Tel Aviv and was a full-time Lehi activist.

After Yair’s murder and the deep crisis which struck the movement, Dov joined the Jewish Guards at Kibbutz Kfar- Hachoresh, and there met Leah Oshrov,  girlfriend and future wife. In 1943 Dov left the Guards, returned to Tel Aviv, dedicating himself to the underground, and  became known as ‘The Tall Blond’, endowed with legendary courage and exemplary strength.  He took part in the attack on British policemen and the assassination of the High Commissioner. He was sent on a guerrilla-warfare course headed by Aviel (Yaacov Eliav), and participated in the attempted weapon confiscation at Tel-Litvinsky. He was second in command of the attack on  CID Headquarters  Jerusalem, where he was severely wounded. He commanded the attack on  Kfar- Sirkin airport in which nine British combat aircraft were destroyed, the operation for the release of  Dr. Yisrael Eldad, and the attack on the Intelligence Building Jaffa. He took part in numerous road-mine missions. In one such event he was again severely wounded  and had to be smuggled out of hospital. The underground sent him on mission to Italy. Upon return he headed the combatants tasked to rid the ‘Sharon’ and ‘Samaria’ areas of the infamous Arab Gangs. When the IDF created the 8^th Brigade, with its 89^th Battalion, he was put in charge of the Lehi Company portion of it, leading them in the battles of Operation Dani. He underwent Officer Training and led his Company to outstanding victories at the battles of both Iraq-el-Suidan and the Western Negev. Dov fell in the battle of Uja-el-Chafir on December 26,1948,  leaving behind his wife Leah, and his brother. The rest of his family were all exterminated in the Holocaust. A senior IDF officer said of him: “Dov was twenty years ahead of his time in pre-empting the IDF’s thinking and development.”

Uri Zvi Greenberg  wrote about him in his poem: “A lament for the zealot, for Captain Dov of the Army of Israel. A blazing Torch was he, inextinguishable by any from among  his enemies.”