Poison

There are a huge number of things which can be considered poisons.

Many poisons are non-fatal in small doses, and it is possible to form an imunnity to many through prolonged exposure. Poisons are one of the many tools used by assassins.

Poisons are also often used in medieval drama. Shakespeare's plays feature many deaths by poison.

A lack of scientific knowledge also lead to people unknowingly poisoning themselves. For instance, Elizabeth I is frequently portrayed with white face make-up that had a lead base. However, this cannot be credited as being the cause of her death.