Yitzhak was born in Odessa, Ukraine, in 1898, to David and Rosa. The family was well-off, and Yitzhak was sent to study in Paris. When World War I broke out, he was separated from his family and had to work. In 1917, he made his way back to Odessa and married Luba Abramowitz. In 1920, the couple managed to emigrate with their young son Yaakov, and they reached Istanbul.
After they settled in, Yitzhak achieved a senior position in the Jewish community and in the Jewish bank in which he worked. He was a Bnai Brith secretary, as this was the only Jewish organization which was then legal in Turkey. In Istanbul, they had two more sons, Mordechai and David. In 1931, Professor Isaac Sachi of the University of Rome, as the personal emissary of Zeev Jabotinsky, and he recruited Yitzhak to the Zionist cause. He then involved himself in recruiting young Jews to Beitar, lecturing them on Zionist ideology. He decided to make aliyah himself. Within a shor time, he had set up a Beitar cell, which had to meet in secret since such organizations were illegal under Ataturk. They would go out on weekend excursions to one of the uninhabited islands in the area, where they would train and play sports, as well as hear ideological lectures.
In 1934, Yitzhak made aliyah with his family, and most of the Beitar members, his students, followed in his footsteps. He continued his Revisionist activity, until he moved on to IZL. While the riots raged in 1936 to 1939, his house was a meeting place and an armory. In his firstborn son Yaakov’s room, there was a closet full of pistols, submachine guns and ammunition. His house was always a place of refuge for the members of the underground, and his wife Luba was always ready to help the young men, even getting a doctor to treat the wounded.
After the split, he was dispirited and ceased his underground activities. However, he soon joined Lehi, helping publish its magazine in French, as well as participating in other operations. The CID tried to break his spirit: they would frequently search his house or question him at his work at Holland Bank, where he was manager. One time Martin came to the bank to tell him his two sons had been killed, and he had to identify them. Martin drove for hours, all the way to Rafiah, but when he saw that Sobol would not respond, he laughed and said it had been a mistake.
Yitzhak Sobol passed away on 15 Shevat 5733, 17 January 1973.
His sons, Mordechai (Tzefoni) and David (Eli), were central and active operatives in Lehi.