In the Mishna (20b) we learn that no one in a courtyard can complain if one of the people living there opens a school for children, even if the children are noisy. The Gemara on our daf explains that this is talking about the time period that followed Yehoshua ben Gamla’s innovation. In presenting his enactment, the Gemara opens with a brief review of the history of Jewish education.
According to the Gemara, it was common practice for fathers to personally teach their children, based on the passage in Sefer Devarim (11:19) that was understood to mean that the main obligation rested with the father. This created a situation where children without fathers did not learn. Recognizing this problem, public schools were opened in Jerusalem, as the prophet Yeshayahu states (2:3) – ki mi-Tziyon tetze Torah – “for Torah emerges from Zion.” Even so, only children with concerned parents were taken to these schools; other children still did not learn. A further advance was the institution of public schools in major population centers, but since it meant travel and living away from home, the children usually came in their late teens, with no formal preparation beforehand. Given their advanced age, youngsters who did not get along with their teachers simply left school.
Finally Yehoshua ben Gamla established a system of elementary schools in every community, where children began studying at age six or seven.
Yehoshua ben Gamla is most likely one of the last kohanim gedolim of the second Temple period, who is mentioned in Josephus as Yehoshua ben Gamliel. If this identification is correct, he was appointed to this position by King Agrippas II.
Yehoshua ben Gamla is praised by the Sages for a number of things, among them donating golden plates for the Yom Kippur lottery, but chiefly for instituting a formal elementary school system in every city in Israel. This led the Sages to say about him, “were it not for him, the Torah would have been totally forgotten.”