Israel Eldad was born in Galicia in 1910 and got his first taste of Zionism when he accompanied his father to demonstrate outside the British Consulate following the 1929 Arab Riots. 

Soon after, he started reading poems by Uri Zvi Greenberg (the father of cultural Zionism) and became deeply immersed in Revisionist Zionist ideology.

Eldad arrived in Mandatory Palestine and joined the Lehi (Stern Group), eventually becoming one of its most prominent members. It was at that time when he began his prolific writing career, spiriting the ideology of the Stern Group.

When Stern Group leader Avraham Stern was murdered by the British, Eldad became its leader along with future Prime Minister Yitzhak Shamir and Natan Yellin-Mor. Shamir was in charge of the operations, Yellin-Mor the politics, and Eldad the ideology.

After Israel's independence, Eldad got a job teaching Bible and Hebrew literature at a high school. He later became a lecturer at Haifa's Technion and Ariel University. In 1988, he was awarded the coveted Bialik Prize for his contributions to Israeli thought. 

Eldad passed away on January 22, 1996. His son, Aryeh Eldad, is a former member of the Israeli Knesset.