Anastasius the Librarian and the shaping of western negative perceptions towards Byzantium
Anastasius the Librarian (810-878 AD) was the chief archivist and librarian of the Church of Rome. Despite being well educated in the Greek language, he was passionately anti-Greek and had made it his mission to "reclaim" the heritage of the Roman empire from its current unworthy custodian "The Greeks" of the eastern empire. In his mind, the Latin West was the proper owner of that tradition and had to reclaim it from "Greek falsity". He made a point of identifying the Latin language as a core part of Romanness (Far more so than any of his precedessors ever did, if they ever did so at all). His writings would have ramifications for the public perceptions of Byzantium in the west that would carry over right to the present.
Anastasius was employed as a translator and ghostwriter for various Popes and by Carolingian emperor Louis II. This gave him the opportunity to voice his views on imperial / ecclesiastical texts and dissemate them widely thus influencing western attitudes. This was also during a time when the papacy was reconstituting itself as a secular authority and attempting to formulate itself as the legitimate Roman authority and "the ruler of the entire world".
From one of Anastasius' writings:
>"The Greeks have ceased to be emperors of the Romans on account of their bad opinions when it comes to religious faith. Also, not only have they abandoned the city and the seat of the empire [Rome] and the language itself [Latin], having migrated in all ways to a different city, seat, people and language [Greek]"
The view in which the city of Rome never lost significance was a new innovation and this sort of attitude presupposed that the eastern Romans werent Romans at all, merely despicable "Greeks". (And not even as the famed Greeks antiquity, who were viewed positively in the West, but rather as devious "modern" Greeks)
There is a widespread belief that Hieronymus Wolf is a sort of devious villain that saught to delegitimize the Eastern Roman empire by conjuring up a new exonym in his writings and that this led to widespread misconceptions in subsequent centuries. However it was not Wolf, but rather Anastasius the Librarian whose polemics had lasting significance and would shape western attitudes of Byzantium and ultimately lead to its downfall and subsequent "orientalisation".
Further reading: Phantom Byzantium by A. Kaldellis