Populations of Constantinople, Cordoba and Baghdad

So, I've been trying to figure this one out for a while now and have been having some difficulty due to the various sources disagreeing.

On the low end, we have Chandler, who claims Constantinople (and Rome at it's height!) never achieved more than 450,000 people.

On higher scale, we have people that claim Constantinople achieved up to 1,000,000 souls at one point, with the likes of Baghdad having 2,000,000 (!) at it's height and Cordoba maybe 800,000.

During Basil II's reign, Chandler puts Constantinople at 300,000 while the highest sources place it at some 800,000 people.

Now, in this cynical age we might be tempted to take Chandler's low estimates as the most 'plausible' and realistic...but keep in mind, this is a man that believes Moses invented Chinese writing.

So, in 1025 AD, at the death of Basil II, where do you think these three cities sat in terms of population?
 
I have a fuzzy recollection of reading Constantinople as of the 12th century being around 400,000.

But I can't remember where.

I'd aim for the low end - the amount of waste, food, and water involved in a city even that big is staggering.
 
Treadgold suggests Constantinople had a population of about 375,000 at its sixth century peak. I think that might be a bit on the low side, personally, though I don't quibble that Constantinople was probably smaller than the Old Rome was at its apogee. I would say Constantinople probably had a pre-plague population of maybe 500,000, down to about 400,000 by the early seventh century. Once the grain from Egypt was removed in 619 and the aqueducts were cut in 626 the population would've gone into freefall, probably down to about 80,000 by 700- though even then Constantinople would've remained much the biggest city of Christendom.

There was clearly the beginnings of a population rebound in Constantine V's reign, and he rebuilt the aqueducts in 767. With increasing wealth and stability, the population would grow. I'd suggest Basil II's Constantinople had a population of about 200K, and this probably swelled still further over the eleventh and twelfth centuries, although the lack of grain dole would've imposed a natural plateau on the population. Probably about 250K by the end of the Komnenid period.

Not sure about Baghdad or Cordoba, I'm afraid. I believe during the tenth century Cordoba and Constantinople were about neck and neck, with Cordoba being perhaps slightly larger. Once the Ummayyads fell in the early eleventh century, Constantinople would remain than larger city forever hereafter. Baghdad, sitting as it did in the fertile plains of Mesopotamia, would have been larger than either. I'd guess for Baghdad at its height a population of anything up to a million.
 
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