As the title says it - is this map authentic? If it is not, where can I find (if it exist) authentic map of that period, and literature about history of Europe in 9th century?
I don't know exactly what you mean by "authentic". There is no such map dating from the 9th century.
The map itself is not very good - it overemphasizes the reach and coherence of a lot of polities. England, for example, doesn't exist, and what did exist certainly didn't look like that.
EDIT: After some discussion with colleagues, we all agree that the map is terrible for many, many reasons.
