Publishers’ lists make it clear that what might be called frills-and-furbelows history is indeed high fashion. The winning formula is relatively simple: identify a group of people with exotic private lives, set them in a courtly or aristocratic milieu, and stir thoroughly. Clothes should be described in some detail, and so should the deviousness of servants, the smell of animals, and the ‘passions’ of the central characters. Colourful language gives a good story real pace.

Such writing carries a sense of awe. For most historians, a day in the archives is a day’s work and nothing more; merely sandwiches and hope. For this author it is much more. Trawling through the archives in Hanover is described as follows: ‘The first morning there, coming into the