I recently ran into mention of Vidocq, would was the founder of France’s equivalent of Scotland Yard, the Sûreté nationale. I only know what I read in his biography on Wikipedia, but he’s an interesting character. He is possibly the first private detective, though perhaps more likely to be the first documented private detective. Interestingly, his being a detective predated the word detective as a noun by quite a few years—not that it would matter, since Vidocq was French.

He had a strange life, spending much of the first third of his life a scoundrel on the wrong side of the law. He eventually decided to turn his life around and so became an informant to the police. After providing them with a fair amount of help, he became employed by them, the Sûreté being founded with his hiring and him put in charge of it. This was during the time of Emperor Napoleon I, and Vidocq would work (on and off) for several French governments before his death. He also supplemented his income with private detection as well as running a private detective agency, though it doesn’t seem to have gone uniformly well.

The Sûreté became the model for many detective police forces in the world, including Scotland Yard. Also Vidocq published an autobiography, which may have even been partially true, which in turn spawned a fair number of entirely fictional stories based upon him or his life; this may well have influenced Edgar Allen Poe when he created the character of C. Auguste Dupin, and with him the genre of detective fiction.