I'm reading the novel Master and Commander by Patrick O'Brian at the moment. It has the following passage in it:
'… it seemed to me there was an unnatural proportion of Lord Mayor's men among them. No old Charlottes, I suppose?'
'Yes, sir, we have one — the fellow with no hair and a red handkerchief round his neck. He was a foretopman, but he seems quite dazed and stupid still.'
'A sad business,' said Jack shaking his head.
The conversation is between a ship's Captain and his second in command, discussing some new recruits they've just brought onboard. The Captain appears skeptical about the men they've been given. I'm assuming that Lord Mayor's men was slang for a criminal element, or otherwise undesirable sailor, but I can't fathom what old Charlottes might refer to. Possibly a survivor of a tragic event around the book's setting (early 1800s)?
I've obviously Googled around to no avail, and I've checked the OED, but I can't find anything illuminating.