Our Gemara relates a story about King Alexander Yannai, who, during the second Temple period returned from a successful war and called to the Sages of the Mishna to join him in a celebratory feast. During that banquet, someone named Elazar ben Po’irah stepped forward and told King Yannai that the Sages were not really his supporters, suggesting to him that he appear clothed as the High Priest (as one of the Hasmonean kings, Yannai came from priestly lineage) by adorning himself with the tzitz (the head-plate) when he came before them. When he appeared wearing the tzitz, one of the Sages called out to him that his position as king should suffice, and that he should not claim the High Priesthood as well. This claim was made based on an unsubstantiated rumor that Yannai’s mother had been a captive in the siege in Modi’in and that he was not truly a kohen.
The celebration ended with tension on both sides, and Elazar ben Po’irah continued his attack on the sages, goading King Yannai into having them killed for their attack on the king’s honor. (The Gemara reports that in response to the king’s question “with the sages gone, who will teach Torah to the masses?” Elazar ben Po’irah responded that the Torah was available to anyone who was interested in opening it and studying, an answer that may have satisfied the need to study the written Torah but not the oral Torah.) According to the Gemara, with the murder of the sages, Torah study came to a standstill until Shimon ben Shatah – whose sister, who was married to Yannai, helped him hide from the massacre – returned to activity and reestablished Torah study.
Josephus recounts a similar story in Antiquities (Book XIII: Chapter 10) where it is told about John Hyrcanus (although the Talmudic sages often refer to John Hyrcanus as Yannai) as the explanation of the break in the relationship between the king and the sages. According to Josephus, at the party the king suggested that anyone who had a critique or comment about the monarchy should share it. Someone named Elazar rose to say that there were rumors that he could not serve as High Priest because his mother had been taken captive by the Greek King Antiochus. When the rumor was checked and found to be untrue the sages punished the man who suggested it with lashes, but that was seen as a mild punishment and the king was encouraged to believe that the sages played a role in the incident. This led to a breakdown in the relationship between the king and the sages.