First published in 1486, Malleus Maleficarum, or The Hammer of Witches, is one of the most notorious works in the history of European witchcraft and demonology. Written principally by the Dominican inquisitor Heinrich Kramer, it emerged at a time when theology, traditional beliefs about magic and developing systems of law were becoming increasingly entangled.

The book is arranged in three parts. The first sets out the theological case for the reality of witchcraft, drawing on scripture, scholastic argument and earlier authorities. Kramer examines the supposed relationship between witches, demons and the Devil, while arguing forcefully against those who questioned whether witchcraft existed at all.

The second part moves from doctrine to the acts attributed to witches. Its chapters discuss curses, harmful magic, demonic influence, transformations, remedies and other practices associated with witchcraft in late medieval belief. Theology sits alongside folklore and anecdote, providing a revealing record of what educated authorities of the period believed — or were willing to accept — about supernatural harm.

The third part concerns prosecution: the investigation of suspected witches, the questioning of witnesses, interrogation and the conduct of trials. This makes the Malleus more than a work of demonology. It is also an important document of legal and institutional history, showing how ideas about witchcraft could be turned into procedures used against the accused.

One of the most troubling and historically revealing aspects of the book is its treatment of women. Kramer repeatedly presents women as especially susceptible to witchcraft, supporting his arguments with the theological and social prejudices of his age. These passages have made the Malleus an important source for understanding the connections between witchcraft accusations, gender and religious authority.

Its influence should not be overstated. The Malleus is sometimes described as the definitive handbook of the European witch trials, a characterisation that gives it more official authority than it actually possessed. Yet its circulation was considerable. Appearing during the early decades of European printing, it passed through numerous editions and became one of the best-known early printed works devoted specifically to witchcraft.

More than five centuries later, Malleus Maleficarum remains a remarkable, disturbing primary source. Bringing together theology, demonology, folklore, gender and judicial procedure, it offers a direct encounter with ideas that helped shape European understandings of witchcraft and persecution for generations.