The hand that rocks the cradle is the hand that rules the world, according to the old saying. Perhaps it should be amended to include "the hand that stirs the soup." For women with malevolent intent (and, historically, little other power), "the weapon was a great equalizer," writes Daniel J. Kevles in a 2006 Slate article on the history of poison. "Murder required administering a poison in repeated or large doses, tasks that women could conveniently perform since they were trusted with the preparation of food and the administration of medicines."
One of the most basic expressions of love, preparing and serving food, has throughout history also been a favorite vehicle for the lovelorn, jealous, desperate, power-mad, or just plain mad, to express their homicidal urges instead. The Elements of Murder: A History of Poison by John Emsley traces this grisly tendency from ancient times to today.
The story of the ancient Roman Agrippina reads like a Greek tragedy. Lusting for the political power she could gain by marrying her uncle, the Emperor Claudius, but already inconveniently encumbered by marriage, Agrippina offed everyone who stood in her way, starting with her husband. She probably dosed them with arsenic trioxide, according to Emsley, "because it was so effective and it enabled her to escape detection."
Being wife of the emperor wasn't enough, apparently; Agrippina wanted her son Nero to ascend to the throne, and quickly. Like an ancient Wanda Holloway, she eliminated his competition, including Claudius's son, and then Claudius himself. Soon after achieving her goal, though, Agrippina learned that being a murderous mother is a thankless job; Emperor Nero gave her a taste of her her own medicine and had her killed (though not by poison).
Poison may have been the preferred murder weapon of women, but its use also crossed gender lines. Both male and female members of the French gentry who hoped to come into money used arsenic to hurry things along. Its use was prevalent enough, Emsley writes, to earn the nickname poudre du succession, or "inheritance powder."
Pope Clement II died mysteriously in 1047, during an infamously corrupt and tumultuous era in the Catholic Church. It was long suspected that he had been poisoned, but t wasn't until 1959, when bone samples were analyzed and abnormally high levels of lead were found, that the theory was apparently confirmed.
According to Emsley, the likely suspect was Benedict IX, who had twice previously been pope—the first time he was ejected for "licentious behaviour" but reclaimed the position briefly before selling the office to his godfather, Pope Gregory VI. When he attempted to reclaim the papacy a third time, he was rebuffed.
It's also possible, Emsley notes, that Clement died of unintentional lead poisoning through copious wine drinking. At the time, German vintners liked to sweeten sour wine with small amounts of litharge, a form of lead. This practice was later outlawed.
One of the most interesting cases in the book, I think, was the mass poisoning of former SS guards awaiting trial after World War II—it sounds straight out of Quentin Tarantino's disturbing revenge fantasy movie Inglourious Basterds. In 1946, a group of Lithuanian Jews who had escaped the Nazis, calling themselves Din (Hebrew for "revenge"), obtained some arsenic trioxide. They smuggled it into a bakery that provided bread for the Stalag 13 prison where the guards were held, and painted the loaves with it. Up to 2,000 prisoners became ill; accounts vary over whether any of them died.
Poison continues to be a popular weapon for murder or attempted murder, whether of Russian ex-spies, Ukrainian politicians, Chinese business rivals or, perhaps saddest of all, Afghan schoolgirls. It's enough to make you want to hire a food taster.