Source Data Reference for:

City = Rome
Time = 1200

City	Year	Size	Size Comment	Year Comment	Author	Title	Location
Rome	1200	35,000			Paul Bairoch	La population des villes europeennes de 800 a 1850
Rome	1200	35,000			Tertius Chandler	Four thousand years of urban growth	p16
Rome	1200	35,000			Tertius Chandler	Four thousand years of urban growth	p538
Rome	1212	18,500	"btw 15,000 & 22,000"		Colin McEvedy	The New Penguin Atlas of Medieval History ISBN 0-14-051249-7	p75