Eliahu was born in Włocławek, Poland to Moshe and Ita on 16.8.1915. He attended the local gymnasium. At age thirteen, he joined Beitar and was one of its operatives. He soon became the district commander, in charge of a number of towns. In 1935, he made aliyah as a student and started studying linguistics in Jerusalem’s Hebrew University. In 1936, he joined the Nationalist Hagana, and during the riots of 1936-1939, he guarded the Diskin Orphanage in Givat Shaul. Later on he commanded the Notrim post in Neve Shaanan. When the Nationalist Hagana split, in 1937, he was among the first to move on to the IZL. In 1938, he was the head of Brit El Al, the first Hebrew corporation at Hebrew University. He was also one of the heads of the Yavneh-Yodfat National Students Union.

When the IZL began training pilots, Eliahu joined the course. He became one of the first Jewish pilots in the Land of Israel. He was one of newsreaders on Kol Zion HaLohemet, the first IZL radio station.

When IZL split, in 1940, he followed Yair to Lehi. In 1941, he was part of the robbery of the Arab Bank in Jerusalem; he dressed up as a British officer. The operation was a failure, and he was captured, tried and sentenced to five years of hard labor. He was at first in the Jerusalem Central Prison; then he was transferred to Nur-Shemesh, to work in the quarries. He was also in Nablus Prison for a while. He ended up spending forty-four months in prison. As soon as he was released, he returned to the underground.

In 1947, he married Ruth Shechter (a Lehi member), and their first son, Yair, was born in 1948.

In 1947, Lehi first open daily was published, HaMivrak, and Eliahu was the editor-in-chief. After the Bernadotte assassination, on 17 September 1948, Eliahu was arrested with many other Lehi members all over the country. He was imprisoned in Jaffa, then Acre, after the prison break. Afterwards, he was transferred to Beit She’an, then to Jalameh. After five months in prison, he was released due to the general clemency issued. In 1950, their second son, Amnon, was born.

In 1955, Eliahu was on the editorial staff of Yedioth Ahronoth. He was a correspondent and a columnist. He founded the El-Am company to publish the Talmud in English.

He passed away on 14.8.1995.

He left his wife and two sons.