Spies & Spycraft
The truth about spying in the Regency is we know little about it. I’ve seen raging debates on author websites in which authors both proclaimed it didn’t really exist and proclaimed the opposite (see the debate here). I would imagine that the point of having spies is not to have them be noticed. Ahem. Anyway, aside from the book mentioned in the comments of the debate, there is also The Man Who Broke Napoleon’s Codes about Sir George Scovell, who was knighted for breaking the French codes. Colquhoun Grant very famously sent intelligence to Wellington as he sneaked around Paris, having escaped his captors. There is some possibility that Mary Nesbitt, too, was a spy. As a courtesan and artist’s model who later became a merchant banker’s wife, she was supposedly sent to France during the Revolution to move in diplomatic circles and report back to English prime minister William Pitt. So, yes, there’s some evidence of spies. Enough for me to use in a book, anyway!