Spies, informers and Thomas Howard’s defence of England’s northern frontier in 1523

Taking the role spying played in the defence of England’s northern frontier against a Scottish invasion in 1523 as its focus, this article examines military espionage during the reign of Henry VIII. After establishing a typology of spying, it analyses the methods English commanders such as Thomas Howard used to obtain intelligence during wartime. It shows that while the principal developments in English spying have been attributed to the reign of Elizabeth I, extensive intelligence-gathering networks were already in place decades earlier and that they played a key role in the defence of the kingdom’s frontiers and the operation of the state. The article also examines Scottish spying during this period and concludes by considering English espionage within a wider European context.