Here’s a couple of maps and some notes to follow on from Who were the Khwarezmians?
In Context… at this time, the last city of the Romans; Byzantium, had just been sacked by the Fourth Crusade. It was incredibly wealthy – most of which was looted by the Venetians. There were few comparable cities in Europe. A couple of centuries earlier, Cordoba – then Muslim – had clocked-in in excess of 500,000 inhabitants. That was as capital of the Caliphate of Córdoba. Andalusia (arabised from land of the Vandals) had since become a place of Taifa emirates (small states); in consequence Cordoba had fallen from its former glory and was a fraction of that size and declining. Population about 40,000, which put it back on a similar scale to other big European cities of the time.
Other Big Cities in Thirteenth Century Europe… the big two were Florence and Venice: 70,000 to 80,000. Further down the scale were cities such as Paris and Kiev (around 50,000). Self-evidently these weren’t on the same scale as Byzantium and the former Cordoba. You can understand one of the motives behind crusaders; loot. Big cities had lots of it and so were a magnet. Back to Byzantium…
once it was sacked it became part of a short-lived Latin Empire. The number of inhabitants (reduced by slaughter etc) fell sharply, making it barely larger than Paris or Kiev. It goes without saying that much was lost with the fall of Byzantium. Even now, the West still haven’t fathomed some secrets (e.g. the formula to Greek/Roman Fire).
Human capital squandered, knowledge replaced by ignorance… And in the horror unfolding further to the East the Tigris ran black with the ink from the destruction of its vast library, and red with the blood of slaughter. Irrigation works that had functioned for thousands of years in Mesopotamia and the Khwarezmian Empire were destroyed and even now haven’t recovered. Those that could have fixed this damage died in the slaughter.