I seem to do a lot of history-based cartoons, often set in the Middle Ages/medieval period. I use these terms very loosely, please don't post, er, pedantic comments pointing out incorrect dress etc.
Sometimes this involves riffing on a specific theme, such as public executions ...
I think I first realised that this is a rich source of jokes when I provided cartoons for the BBC's short-lived Robin Hood Adventures magazine some years ago. There's more historical hilarity here, and here and here.