The most obvious problem in writing a history of poison pen letters is that only half the story can be told. Whodunnit and why must often remain a matter of speculation. Even if the culprit is identified, their motive for writing tends to be clouded.

What, for example, persuaded the eminently respectable Winifred Simner to wage an unrelenting letter-writing war against the councillors and officials of Wimbledon borough council throughout the 1930s? She accused a local councillor of defrauding the Poppy Day appeal, being a bigamist and many other things (‘too old’, ‘not a fit man’, ‘he has no education’, ‘an absolute rotter’). She accused the town clerk of taking bribes and the council of appointing too many Catholics. After being caught, she was tried at the Old Bailey but, being ‘a woman of … position and education’, in the judge’s words, she was sentenced only to probation. She could certainly spell correctly. Members of the lower orders who were caught writing anonymous letters usually got hard labour.

The author of Penning Poison, Emily Cockayne, associate professor in early modern history at the University of East Anglia, tends to be slightly more forgiving of women poison pen pushers than men. Women have tended to be accused of being driven by sexual frustration, whereas men have got away with