In 1933, a 7 or 8-year-old Yaacov threw stones at members of Beitar who were walking the streets of Tel Aviv on the seventh day of Passover, and even stole a knife from his mother in with the intention of attacking Beitar members. Years later, he became a member of Beitar and after that, a member of Lehi.
It seems, his initial last name was Mendelson. In 1941, Yaacov ran from his family home in Tel Aviv and set sail with a Danish cargo ship. According to him, the ship sank and he was rescued by a ship of Jewish fishermen from the island of Crete. Yaacov returned to Israel, enlisted in the British Commercial Fleet, helped deliver ammunition and supplies to the British in Tobruk, and in the mid-1940s, he joined Lehi. On June 3rd, 1945, Yaacov sailed abroad again at the request of Yitzhak Shamir, to mobilize sympathizers and fighters to free Israel. It is not known when he returned to Israel, but he was on the last ship of detainees deported to Africa, and in May 1947 he was held in a camp in Kenya. He returned to Israel with the last of the exiles on July 1948.
While in custody, he published articles in the journal “Badad”, and after the independence of Israel he continued to publish articles and stories. He was a high school literary teacher in Tel Aviv, he edited the Journal of the Association of Sailors in Israel (1952-57), and then moved to the United States, from where he sent articles to publish in newspapers in Israel and abroad. In 1959 he won a literary award from the Merchant Navy Writers and Artists Club, and in 1965 he won the “Bitzron” award for short stories.
Over the years, Yaacov worked under various nicknames and names. In 1967 he began to write the surname as “Haramgal” and returned to use his real first name, Yaacov.