Claudius, the fourth Roman emperor, died suddenly after a banquet, with ancient historians including Tacitus and Suetonius alleging his wife Agrippina the Younger poisoned him with a dish of mushrooms to secure the succession for her son Nero over Claudius's own son Britannicus. Whatever the exact cause, his death triggered the swift installation of the teenage Nero as emperor, beginning one of Rome's most notorious reigns.
Claudius had come to power in AD 41 almost by accident, discovered hiding behind a palace curtain by the Praetorian Guard after his nephew Caligula's assassination. Despite a limp, stutter, and years of being dismissed by his own family as a fool, he proved a capable administrator, expanding the empire into Britain and reforming the bureaucracy.
His fourth wife, Agrippina the Younger, was ruthlessly ambitious, and historians of the era claimed she maneuvered Claudius into adopting her son Nero and naming him ahead of his biological son Britannicus in the succession. When Claudius began showing signs of favoring Britannicus again, ancient sources say Agrippina acted first, serving him a plate of poisoned mushrooms, a delicacy Claudius adored, at a private dinner.
Modern historians debate whether Claudius died of illness or murder, but the political effect was undeniable. Within hours of his death being announced, the Praetorian Guard presented seventeen-year-old Nero to the public as emperor, bypassing Britannicus entirely. Agrippina had secured her son's throne, though within a few years Nero would have her killed too, a grim pattern of imperial succession that Claudius's death set irrevocably in motion.