Then it was subverted and invaded.
Marxists-leninists (so called) of course didn't enjoy the fact of Socialism existing before feudalism - which didn't fit into theory.
Now there's a myth "they were savages, half-beasts before Cyrill and Methodius,
couldn't write". While in fact Novgorod had letters exchanged between lowest ranks of society. But the myth is profitable
to both marxists and "traditionalists".
History is written by invaders.
Oh yes, certainly. They only need to make the stories work for themselves in order to present a certain viewpoint to further their agendas. Perception management. This happens a lot during wars because they want to lay the blame on the other side. Also in terms of casualty numbers in order to make it seem worse than it really was.
Most people of Turkey believe right now that the USA is directly responsible for their currency crisis when in fact it was them who instigated it. But they have the support of most of their population, so it's all that matters.