The Pisonian conspiracy was a plot to assassinate the Roman Emperor Nero in AD 65, led by Gaius Calpurnius Piso. Piso was a prominent senator and nobleman who was dissatisfied with Nero's leadership and wanted to overthrow him. The conspiracy involved a number of other high-ranking individuals, including members of the Roman Senate, and was intended to take place during a public performance of the emperor's musical compositions.
However, the plot was uncovered by one of the conspirators, and Piso and his associates were arrested and executed. The Pisonian conspiracy is significant in Roman history because it represents one of the most serious threats to the stability of the Roman Empire during the reign of Nero, and highlights the tensions and conflicts that existed within the Roman elite at the time.