You hear a lot of stories about people being poisoned back then, kings, queens, nobles, etc. what sort of poison was so readily available back then and how was it manufactured?
In Roman times it was mainly vegetable based poison. Examples of these plants are deadly nightshade which contains belladonna alkaloids, hemlock, and yew extract which contain aconite. Animal based poisons were not fully understood at the time so they were not often used for homicide.