Yohanan ben Zakkai was a Jewish sage of the first century of the common era, and a primary contributor to the core text of rabbinic Judaism, the Mishnah. He was an important sage in the era of the Second Temple in Jerusalem, and re-established the Sanhedrin after the destruction of the Temple in 70 C.E.
The Mishnah offers no information on his birth or family. He is recorded as living until the age of 120 years.
He is said to be a pupil of Hillel. He is known to have studied in Jerusalem, in the Land of Israel, and then went to the Galilee.
He is credited with originating several ritual innovations that made it possible to replace animal sacrifice lost with the destruction of the temple with prayer. In this post-Temple period, rabbinic tradition records a restructuring in prayer services to make this transformation possible. However, Yohanan Ben Zakai was not the only Rabbi from that time period. Other Rabbis that contributede to the mishnah include, Ben Heyhei among others
JohananbenZakkai was a member of the Great Sanhedrin in Jerusalem, the assembly of 71 ordained scholars that functioned both as supreme court and as a legislature.
Johanan foresaw that the Jews could not be victorious in their desperate struggle against Rome; he was determined, however, that Judaism should not perish even if the Jewish state and the Temple were destroyed.
Johanan was not formally designated as Nasi, prince or head of the Sanhedrin, probably because he was not a descendant of Hillel or of Davidic stock, as Hillel was.