King Mithridates is a well-known figure to historians of toxicology. He had a large library of toxin related essays and was said to use poisons on both his family members and rivals! Supporters of the king used mad honey to poison Roman soldiers during war.
Historic Poisonings Archive
Poisonings Throughout History: Olive Thomas
Olive Thomas was a well-known model and silent-film actress in the early 1900s. She died from what was likely accidental poisoning of mercury bichloride.