Yitzhak was born 1922 in Turkey. His parents Malka and Shabtai, made aliya that year, settling in “Little Tel-Aviv”. He graduated from “Alliance” and was educated in the Etzel National Cells. He belonged to the “8th Company”, led by Arieh Yitzhaki and Yitzhak Shamir. He participated in operations upon facilities of the British Mandate government and in retaliatory acts against Arabs. He was working then at the Post-Office, where he was tasked to spy on the British and the Jewish Left. After Etzel split he joined Yair and Lehi, chiefly because Lehi command was of the opinion the fight against the Arabs was not as important as the fight against the British rulers. Using his codename ‘Lavan’, he distributed leaflets against enlistment in the British Army. He was Yair’s contact person while Yair lived at Balfour St. 57, Tel Aviv. After Shamir and Eliyahu Gil’adi escaped Mizra Detention Camp 1943 and Lehi reorganized, Yitzhak underwent weapons and sabotage courses, was involved in raising funds, and procuring additional weaponry. During the ‘Saison’ of 1944-45 Yitzhak formed an intelligence unit to counter Haganah members that were spying on Lehi. When the Saison terminated, he was charged with reorganizing Department Six (Intelligence) and put in charge of the Jerusalem branch – positions he continued to hold following Shamir’s arrest and during Nathan Yelin-Mor’s leadership. Under Yitzhak, Department Six became a national branch. His other codenames were ‘Yossi’ and ‘Lot’. Yitzhak resigned from Lehi following disagreements with the Center regarding the movement’s future. He joined the Palmach, then the IDF where he served during the War of Independence. After the war he set up plant nurseries and a development contracting company. He participated in International Humanist congresses and the peace meeting with the PLO in Romania. In 1976 he established an atheist movement, ‘Israel Secular Humanist Association’. In 1993 he published his book ‘The Old Man and I’, a personal story of Lehi’s Intelligence Chief. He also published ‘Stories of Solomon’ and ‘Grandpa Itzik’s Stories’, a collection of tales for children. Yitzhak is married to Sarah, a fellow Lehi member. They have three children.