The fear of witches and witchcraft has a long history in Europe, and common beliefs about witches can be found in the portrayal of the “three weird sisters” in Shakespeare’s Macbeth. Witches were usually, but not always, women, and could trigger suspicions of witchcraft by engaging in unconventional lifestyles, such as living alone or in isolation from a community, just as the witches in Macbeth are presented as at odds with society, living by themselves on the heath and begging for food. Witches usually also had “familiars” to carry out tasks for them; these could take the form of animals such as cats or dogs. When we first see them, the witches in Macbeth refer to their animal familiars of Graymalkin (a cat) and a paddock (toad). While she is presented in different terms, Lady Macbeth’s allusion to summoning up demonic spirits to help her carry out her plan in Act 1, Scene 5, would also possibly have invoked ideas of witchcraft, especially given the sexualized language she uses. Audiences were likely to believe that women became witches by consenting to sexual intercourse with the devil or some other evil spirit.

In 1542, fifty years before Shakespeare wrote Macbeth, King Henry VIII passed the first English Witchcraft Act, which officially made the practice of witchcraft punishable by death. Henry was motivated by the religious tensions triggered by his earlier break from the Catholic church, but he might also have been wary of the powerful influences women had held over him. When his second wife, Anne Boleyn was tried and executed for crimes including adultery and treason, there were also charges that she had practiced witchcraft and used magic to trick and seduce the king. This first Witchcraft Act was repealed by Henry’s son Edward, but a new act was passed shortly after Elizabeth came to the throne. This act stipulated death to anyone found guilty of using witchcraft to harm another person. Some historians have argued that at a moment when a woman independently ruled, anxieties about female power and influence became more pronounced, leading to sterner penalties for suspected witches. Similarly, in addition to the explicit presence of witches, Macbeth also features a strong-willed and domineering woman, suggesting that Shakespeare also saw these themes as interconnected.

King James, who ruled England when Shakespeare wrote Macbeth, was convinced that a group of witches were plotting to bring about his death and played an active role in the North Berwick witch trials, which implicated dozens of people on witchcraft charges and led to multiple executions. He also methodically researched and wrote about witchcraft, publishing his book Daemonologie in 1597. This work was a detailed account intended to inform the population about the origins and practices of black magic, as well as make a theological case justifying the persecution of witches under Christian law. Some of the actions and language Shakespeare attributes to the witches in Macbeth appears to have been sourced from this text. For example, James wrote about the ability of witches to either curse men with impotence or achieve the same result by exhausting them with repeated sexual encounters. In Act 1, Scene 3, the first witch describes her plan to torment the sailor: “I’ll drain him dry as hay” (1.3.18) and “I’ll do and I’ll do and I’ll do” (1.3.10), suggesting that she will leave him exhausted and sleep-deprived by repeatedly having sex with him.

In 1604, right after James ascended to the English throne, a new Witchcraft Act was passed, extending the scope of witchcraft-related crimes that could be punished with death. Considering the king’s well-known interest in witches, Shakespeare likely thought James would approve of this content in his latest play. As James’s reign continued, he would become more skeptical about the possibility of witchcraft. However, charges of witchcraft continued in Great Britain, with Scotland in particular experiencing a number of witch hunt crazes throughout the 17th century. Later that century, the Salem witch trails rocked New England. Historically, periods of intense concern about witches and witchcraft tend to overlap with periods of political instability, uncertain leadership, and anxieties about power dynamics. By combining the presence of witches with similar themes in the world of Macbeth, Shakespeare used witchcraft to signal to his audience that Scotland was in a vulnerable and unsettled state. What made witches dangerous was their overweening ambition and willingness to sell their souls in order to achieve power (in their case, supernatural rather than political). Likewise, Macbeth falls prey to the same tendencies.