Darius I seized the Persian throne in September 522 BCE after killing Gaumata, whom he claimed was an imposter pretending to be Cambyses II's brother Bardiya. The new king immediately faced widespread rebellions across the empire—in Persia, Media, Babylonia, Elam, and Egypt—but crushed all nine rebel leaders within one year through military campaigns that he immortalized in the famous Behistun Inscription. During his 36-year reign until 486 BCE, Darius transformed the Achaemenid Empire into hist