Look. I'm not a/an historian, right, I merely watch a lot of documentary television. I'm most partial to historical programs and Monday night there were two from Channel 4. (A veritable font of docos, by the way.) At 8:30 there was London: The Greatest City on The History Channel and at 10:30 The Great Plague was on my ABC.
From what I can tell, keeping in mind there may well be some valid
excuse reason for the anomaly, Channel 4 may need someone to cross-check their material.
"By winter (1665) the plague had wiped out 100,000 people. One fifth of the city's entire population."
Channelling Isaac Newton's apple, that makes 500,000 people - quite the bustling metropolis by 17th century standards. So it was with some degree of interest when, not two hours later, my lugs pricked up at the following:
"The population of London in 1665 was 300,000."
Typed, trebuchet answers on my desk, well, in the comments box, anyway, by the usual date, please.