The Annals and the Histories · Ann. 12.66

Under this great burden of anxiety, he had an attack of illness, and went to Sinuessa to recruit his strength with its balmy climate and salubrious waters. Thereupon, Agrippina, who had long decided on the crime and eagerly grasped at the opportunity thus offered, and did not lack instruments, deliberated on the nature of the poison to be used. The deed would be betrayed by one that was sudden and instantaneous, while if she chose a slow and lingering poison, there was a fear that Claudius, when near his end, might, on detecting the treachery, return to his love for his son. She decided on some rare compound which might derange his mind and delay death. A person skilled in such matters was selected, Locusta by name, who had lately been condemned for poisoning, and had long been retained as one of the tools of despotism. By this woman's art the poison was prepared, and it was to be…

Cornelius Tacitus · trans. Church & Brodribb, 1876
Source edition
Passage preview. Read in context for the complete text, notes and references.