Not sure if this goes here, but I couldn't work see a literature stack exchange...
In the Sherlock Holmes story A Study in Scarlet, I have always wondered about the following passage:
'"I have my old service revolver and a few cartridges."
"You had better clean it and load it. He will be a desperate man, and though I shall take him unawares, it is as well to be ready for anything."
I went to my bedroom and followed his advice. When I returned with the pistol the table had been cleared, and Holmes was engaged in his favourite occupation of scraping upon his violin.
"The plot thickens," he said, as I entered; "I have just had an answer to my American telegram. My view of the case is the correct one."
"And that is?" I asked eagerly.
"My fiddle would be the better for new strings," he remarked. "Put your pistol in your pocket. When the fellow comes speak to him in an ordinary way. Leave the rest to me. Don't frighten him by looking at him too hard."
"It is eight o'clock now," I said, glancing at my watch.
"Yes. He will probably be here in a few minutes. Open the door slightly. That will do. Now put the key on the inside. Thank you! This is a queer old book I picked up at a stall yesterday—'De Jure inter Gentes'—published in Latin at Liege in the Lowlands, in 1642. Charles' head was still firm on his shoulders when this little brown-backed volume was struck off." "Who is the printer?" "Philippe de Croy, whoever he may have been. On the fly-leaf, in very faded ink, is written 'Ex libris Guliolmi Whyte.' I wonder who William Whyte was. Some pragmatical seventeenth century lawyer, I suppose. His writing has a legal twist about it. Here comes our man, I think."'
Were Philippe de Croy or William Whyte connected to any of the historical people with those names?
If your answer is, 'no, he made them up' I will be happy to upvote it... if it has sources :). I googled around it, but it's hard because it's a famous public domain book and you mostly get that passage reflected back at you.