Also damn, I was re-reading the update and realized I totally forgot the notes...... Crap, sorry-I inserted them, and here is the copy paste so that you need not re-read it all.
Notes:
[1] Apocarius: Papal legate to Constantinople. The Alexander in question later became Pope (as noted in the chapter) and wrote
History of the Roman Empire - the standard text concerning the Latin Empire (Principate and Dominate) which runs from Augustus to Phocas. This work of scholarship took much effort, and extensive perusal of documents in Constantinople and is the only material that preserves contents of major Latin writers whose works were burned by John Callinicus.
[2] Alp Arslan becoming Leo: Alp Arslan means "Heroic Lion" in Turkish. Leo was thus the obvious choice for a baptismal name.
[3] Nestorian Seljuk: Seljuk had only converted to Islam in 985, and he had sons called Michael and Israel, suggesting a Nestorian past (not really, but that is the TTL belief).
Vasilas' Notes:
(1) The incendiary was gunpowder. The reason they are unwilling to admit that is because they stole the recipe from China (like Justinian and Silkworms, but here is was just a quick Greek note no one could read). Professor Andronikos Doukas (who had accompanied the Fatimid embassy to China right before Dawd's coup and had only returned when Egypt was under the Empire) had been very busy in his time at the East. He did not get the recipe at the time, but saw some of it in action and was in any case convinced that stealing tech from China was in the best interest of the Empire. The distance makes things difficult (the lost last voyage of Basil II being a big example of some issues) but Basil III's interest in trade as well as co-opting Arab sailors knowledge about routes led to a small permanent mission in Guangzhou by 1040s. An enterprising alchemist who travelled with a mission at this time was lucky enough to learn what exactly the "fire lances" were using and immediately jumped on the next ships back (with extensive coded notes in Greek in case he did not make it). The classic secret protocol (as followed with Greek fire) resulted, and they barely had working prototypes (basically barrels and wicks) going in time for Manzikert. Gunpowder would however only be openly used once it became clear that power/s threatening the Empire also had Chinese powder and so secrecy was more hindrance than help.
They don't quite want to come clean as they have insisted for centuries that they invented it independently (later, but nonetheless without any Chinese influence). Several people they have used to make that claim (who in most cases did not know any better, as they didn't dig eleventh century secret records) are too highly regarded in society (a couple of Emperors, a few bigshot scientists etc) for the prideful Empire to come clean about the lies. Societies are often proud to the point of irrationality, and a surviving Romania is going to be an extreme case because of its history. There is also the precedent of Greek fire, and so most people do believe the claim to be a real one.
(2) Alp Arslan converted because of the kindness of Emperor John. He simply could not believe that such a person could have led his Empire to victory, or indeed last as Emperor in the violent world-not unless he had friends in high places, such as whatever power that defeated the Turks at Manzikert.
(3) Marcionism and other Gnosticism: John II was increasingly being convinced that the Old Testament God could not be the same one as the New Testament one. One preached forgiveness and the other was a genocidal psycho so to say, and he was clear about which one he backed. By the end, he saw the Islamic/Judaic God as a malovolent entity enticing humans astray (the Demiurge-lord of the material world), while the Christian God's fundamental message was salvation-though the Church was corrupted by the Demiurge itself. He was however not loony enough to actually say this openly or act in a manner that would suggest he thought this way. That being said, he also refused to go to the other end and persecute other gnostics like the Paulicans/Bogomils, leading to his eventual downfall (yep, he was poisoned off).
John is not an actual Cathar/Bogomil/Paulican though-just to be clear. He would identify as a Marcionist in the modern era. That being said, his ideas did not develop in a vacuum but owed quite a bit to the intesting neo-Gnostic ideas floating around in Roman society's fringes at that time.
The wikipedia article on Marcionism may be of help if anyone wants to have a quick look at this:
https://en.wikipedia.org/wiki/Marcionism