Sadly I do no know well the history of the birth of the first Russian state, but maybe all the people here are saying the same thing using different words?
Vikings from Sweden, powerful Steppe Peoples, Slaves expanding their influence, Frankish Carolingian Germans.... all these people fhighting for supremacy in the same lands, meanwhile excanging cultures, goods and languages, don't could be possible that the same king could be called in different ways, Kunig, Kagan or Konig......from the various people who lived in that geographical area?
I know that the words are important; words like Byzantine/East Romans can be used to indicate two very different approach to the same historical entity!
But here not! Here I do not see this! Here I see some different sources which use different languages to describe probably the same thing: the glorious birth of the first Russian Slavic Principate!
After my beloved Lombards, the Rus will be my army!
Here I saw really a great work!! Thank you Mod Team and researchers!!