Other characters in this book may seem at first reading to be the product of a vivid imagination but there really was a mysterious "Mr. Smith" who detached Fulton from Napoleon to transfer his allegiance to England. There is very little known on this episode so I took what I felt was likely to have occurred, and put Renzi in Smith's place. Likewise, the famed Parisian savant, LaPlace, was indeed a friend of Fulton's . . .
I enjoy Jane Austen's works and it was on a literary whim that I decided to mention her in Invasion, via her brother who actually was in post there at the time. She in fact had two sailor brothers: Francis, who Kydd meets in the course of his acquaintance with the Fencibles, and Charles. Both later advanced to become admirals and Jane no doubt consulted them when she created William Price in Mansfield Park and Captain Wentworth in Persuasion.
As usual, I owe a huge debt of gratitude to many people. I cannot acknowledge them all for space reasons but deep thanks are due to Rowena Willard-Wright and Joanne Gray of English Heritage, who arranged special access to Dover Castle, Fulton's base while he was working on his inventions, and Walmer Castle, where Pitt lived and which he used as a secretariat for his clandestine operations against the French. And of course I would be remiss not to mention my literary agent, Carole Blake, and my new editor at Hodder & Stoughton, Anne Clarke.