One could say the Egyptians were defeated by madness: having Al-Hakim in any position of power is unlikely to work out well for the people he is responsible for. Structurally yes. they fell due to actually thinking they could take Anatolia alongside the Armenians, and forgetting that Winter was Coming. If they had stuck in the Levant, they could have actually done something like the 638-640 period when the Empire held Egypt but had lost the Levant. It would have been tremendously difficult to uproot them for there if they had dug in, and at some point of time the Empire would have given up to just be happy with Egypt. Roman military superiority itself was not really the biggest deal-they got bogged down in Egypt, were on the defense in Edessa and Yarmouk was a clash between professional troops on their side against reluctant conscripts. This was probably one time they did not even have a decisive numerical advantage, but the naval supremacy allowed them to put their numbers to the best possible use.So the Egyptians are defeated through a combination of General Winter (Of a minor scale), Moses' plague, and good old fashion Roman martial superiority. Great update!
Does this Alexander Komnenos have any relation to any OTL people?
The plague just proved to be an icing in the cake. At best it shortened the complete conquest of Egypt by a year (perhaps even less, as the Romans themselves had slow down in order to help Melkites).
Alexander is a natural son of Manuel Erotikos (thanks for that suggestion!), born during the previous Syrian campaign when Manuel Erotikos was a mid level officer in Basil's army. Not quite an orphan, but is certainly someone daddy dearest felt more comfortable gifting to the Empire than raising as his own kid. Being related to Greek nobility meant that he was always on the fast track for leadership. He is extremely young (born in 979) but so is the rest of the Orphans, and they had been trained for war since birth (plus Basil was even younger at the time of Baghdad). Yarmouk cements his position as a legendary commander, and I'd be a bit worried if I were Isaac.
Not quite. The Middle East was still majority Christian at the time, so the blow has been rather uniform. Egypt is a total wreck where only the Melkite population had held steady courtesy the flow of grain from coreligionists. But both Copts and Muslims have been screwed over epically. In the Levant on the other hand there has been a massive anti-melkite genocide in the interior, leaving a lot of the interior very muslim (conversely the coasts are uniformly Christian-all muslim males were killed and the rest driven out to preserve food the moment the Empire realized the depth of their problem). Constantinople would not be a huge fan of that, but they may not have a choice if they want a functional economy. There is a major demographic hole overall in the non-Greek bits of the Empire, but I don't think it can be filled with migration (without damaging the Balkans/Anatolia in the process). Are you thinking of Turks? Because the Turkification of Anatolia was a cultural process than genetic-the DNA of the locals matches up quite nicely with old mummies in the region, and so a migration of that sort will not likely fill the hole.Does this mean that the demographics of the Muslim middle East are completely destroyed through a combination of war and famine? Guess the region is ripe for a new group to come and... Settle in.