As has long been recognized, Judaean tyranny, especially that associated with the revolutionary faction led by John of Gischala, plays a central role in Bellum Judaicum, functioning as an infectious disease that ultimately bears responsibility for the destruction of the temple in Jerusalem. Among the litany of damnable vices associated with John and his band of followers, Josephus paints a particularly lurid picture of violent debauchery in B.J. 4.560–563, recounting a blood-drenched sexual rampage that includes a pointed accusation of cross-dressing and sexual passivity. In this article I argue that Josephus' portrayal of the Judaean rebels as effeminate objects of sexual penetration draws on a widespread tendency in Greco-Roman discourse to link perceived gender anomalies with an excessive and uncontrollable lust for power, deploying gender deviancy as a symbolic framework through which to define and disparage tyrants. This image of effeminate tyranny in B.J., although dubious as a source of reliable information for the Gischalan's exploits in Galilee and Judaea, taps into a resurgent moralizing impulse in Flavian Rome, offering an important glimpse into Josephus' own attempt to navigate the cultural and political anxieties of the capital city shortly after the tumultuous transition from the Julio-Claudian to Flavian regime.