Zealot coup in Jerusalem

The Zealot coup in Jerusalem was a violent seizure of power in 66–68 CE, in which the Zealots, a radical Jewish faction, overthrew the moderate government established at the outset of the First Jewish–Roman War (66–73 CE). The coup marked a turning point in the growing internal conflict among Jewish factions resisting Roman rule. The zealot coup took place as Vespasian's forces were concluding their Galilee campaign, while Jerusalem faced mounting instability due to an influx of refugees and rebel fighters.

Led by Eleazar ben Simon, the Zealots executed prominent figures accused of collaboration with the Romans, seized the Temple precinct, and replaced the traditional high priesthood with Phannias ben Samuel, chosen by lot. Moderate leader Ananus ben Ananus gained popular support and began raising an army to challenge the Zealots. In response, the Zealots launched a counteroffensive, but were outnumbered and forced to retreat and fortify themselves in the Temple. Urged by John of Gischala, they summoned the Idumeans, who entered the city under the cover of a storm and aided in the massacre of the moderates.

Following their victory, the Zealots and Idumeans established tribunals, killed their opponents—including Ananus, Joshua ben Gamla, and Niger the Perean—and solidified control through terror and purges. Many Idumeans later withdrew, while some joined the faction of Simon bar Giora. The internal violence led many to flee the city, and according to Josephus, convinced Vespasian to delay his assault on the city, believing the Jews were destroying themselves without Roman intervention.