Shaul was born on May 7, 1915 in Riga, Latvia, son of Israel Shmuel and Esther. He studied in a public Hebrew school, where he joined Beitar. His father fought in World War I, and even fought alongside Trumpeldor, so he was influenced by reading about Beitar. He encouraged his son to join. However, in 1928, when Shaul joined Beitar, his father had already passed away.
He made aliyah in 1935 and joined the local Beitar chapter, first in Hadera, then in Zikhron Yaakov and in Ekron. When the farmers of Nes Ziona sought protection of their orchards in Ashdod (as Arab rioters had uprooted some of their trees), Shaul moved there. Unfortunately, he came down with typhus and was transferred to the Tel Aviv Hospital. When he recovered, he stayed in town and started working in printing. He also established a small underground press.
When Lehi was established, he joined, and he continued working as a printer. When the press was moved to a new location, he was caught and lost his contacts with the underground. Soon he was able to reestablish the connection, this time with Yitzhak Shamir. One time, when he had to give a message to Shamir, he arrived at his apartment only to find out he had been arrested. The connection was lost once again.
In May 1942, he enlisted in the British Army, and when he reached Egypt, his links to the underground were renewed. He would smuggle weapons from Egypt to the Land of Israel in small quantities. One day, he was told to accompany Eliyahu Hakim to Egypt; soon after, he was ordered to bring in Eliyahu Bet-Zuri as well.
After the war, when he returned from Europe to Rehovot, he was arrested and sent to Latrun, where he spent nine months. Once he was released, he returned to work at the HaMashkif newspaper. He then moved on to Herut when the State was established, then Maariv, until he retired.
He married Shoshana, and they had two daughters and numerous grandchildren.