Source Data Reference for:

City = Istanbul
Time = 800

City	Year	Size	Size Comment	Year Comment	Author	Title	Location
Constantinople	700	400,000			George Modelski	World Cities -3000 to 2000	p49
Constantinople	737	87,500	"btw 50,000 & 125,000"		Colin McEvedy	The New Penguin Atlas of Medieval History ISBN 0-14-051249-7	p41
Constantinople	800	400,000			George Modelski	World Cities -3000 to 2000	p49
Constantinople	800	250,000			Tertius Chandler	Four thousand years of urban growth	p14
Constantinople	800	250,000			Tertius Chandler	Four thousand years of urban growth	p467
Constantinople	800	300,000			Tertius Chandler	Four thousand years of urban growth	p528
Constantinople	800	250,000			Tertius Chandler	Four thousand years of urban growth	p531