Rabban Gamliel II, grandson of Hillel and head of the Sanhedrin at Yavneh in the generation after the destruction of the Second Temple in 70 CE, was a brilliant man with a hard streak. He insisted on decorum in the academy, and he was not above humiliating a colleague to enforce it. On one occasion he forced Rabbi Yehoshua ben Chananiah to stand humiliated during Gamliel's own lecture, publicly silencing a man whose knowledge was fully the equal of his own.
The sages present were outraged. This was not the first such incident. After long discussion, they removed Rabban Gamliel from the presidency. In his place they appointed Rabbi Elazar ben Azariah. He was only eighteen years old, a sage of deep learning but worrying youth. So that he might command the respect of his older colleagues, a miracle was granted. His black hair turned white overnight, and he looked in the morning like an old man. Rabbi Elazar is said to have remarked afterward, Behold, I am like a man of seventy years.
Elazar's administration was milder than Gamliel's. On his first day he removed the guard from the doorway and admitted every student who wanted to learn. Hundreds of new benches were added. Meanwhile Gamliel, at home with his disgrace, dreamed of pitchers filled with ashes. He woke comforted. The pitchers, he decided, meant the new students were unworthy, empty vessels dusted with pretense. His own stricter admissions policy had been correct.
But the dispute was eventually settled. The sages, preserving dignity on both sides, restored Rabban Gamliel to office, but only as the colleague of Rabbi Elazar, though Gamliel was his senior in both age and rank. This story, preserved as exemplum 169 in Moses Gaster's 1924 Exempla of the Rabbis and told at length in Berakhot 27b-28a, teaches that even the greatest leader can be deposed when his pride tramples a colleague, and that the academy belongs not to the president but to the Torah.