LloydBrown said:
Somewhat. Maps I can find. Maps with a scale I can't find.
I have an awesome book called "Daily Living in the Twelfth Century, Based on the Observations of Alexander Neckam in London and Paris," by Urban Tigner Holmes, Jr. It's from the U of Wisconsin Press, 1964. Obviously it's London and Paris, not Rome and Florence, but we're still talking major European cities--close enough, if all you need to know is size/scale/population type info. It's amazing how little of the modern cities there was back then; it was just the center.
Anyway, maybe that particular book isn't hugely useful for you, but from looking at the maps in it I have a suggestion: get medieval maps without scale. Then get modern maps of the same cities (Florence, Rome, whatever), to scale. Then compare the medieval and modern maps... you'll see some landmarks and possibly some natural features that will enable you to guage the size and scale of the medieval city, by comparison to the modern city. You could even blow the maps up until they're both the same scale, and superimpose them to get a better idea. Voila.
Here's a cool site about ancient/early medieval Paris. Maybe it will give you some ideas.
http://www.paris.culture.fr/en/index.html
