How does it work? After so many dynastic marriages its rich suggesting some non local origin.
You can`t even imagine how close you are to understanding but, still you fails.
Listen. Ancient Slavic world was inter-continental. Spread wide, same as it is today, no matter reduced. From what is now Scotland and western Europe to the Ind River in India, all the way via Caucasus and Siberia, what is now Iran (Persia), etc. From Baltic and Northern Europe (Prussia), South-Eastern and Eastern Europe to what is now Spain, Anatolia, Near East, parts of Africa.
How understanding of local origin shifted?
See, all around bordering regions of their realm and on their seas, or even deep in its own inland, in big trade centers that attracted foreign traders (and intruding armies), our ancients had encounters with strangers. Barter, trade and conflicts were first reasons for contacts. To shorten this elaboration I would only say that those encounters resulted in formation of hybrid societies (as result of foreign economic, cultural and linguistic influence) on the fringes of realm of the ancients. In some cases those foreign influences were predominantly culturally based and in some cases in addition were followed by heavy interbreeding of population. For example, in examples such is Baltic, foreign influence was predominantly cultural, linguistic with additional mixing of ruling classes with foreign traders and even with foreign ruling classes. On the other side, on examples such were Troja, we must presume that ancients were in addition exposed to heavy mixing of their populous with foreign peoples and tribes. So, with time, once when you had established ruling class that had truly unique local economic interests, local hybrid culture and in some cases ruled over population that received cultural or even genetic foreign element, that local ruling elite tended to separate from rest of Slavic world, to increase investment in its unique position, in order to achieve even faster and bigger personal enrichment.
In that situation, crucial problem for the ancients was that those were exactly biggest trade (economic) centers that fall to the foreign influence. Practically, almost that one can say that urban centers betrayed rural population. Elite from the big city centers confronted rural elite. World of our ancients was torn apart. And it was already acute problem much before God even had plans for Egyptians, Greeks or Romans.
Imagine proportions of internal conflicts within realm of ancients. Antagonistic forces erupted. Back then there was no internet and people were not that well connected. What local ruler says, that was law. Sure, local rulers had to confront still dominant native Slavic culture. There was religious caste that tended to preserve unity of Slavs for its own interests.... no wonder that Romans (as documented) so passionately exterminated priests of ancients whenever they could. Romans who had interest to prevent big uprisings of population and arise of united respond against them. See, just imagine agony of ancients. Agony of those few who were truly aware of proportion of threat and tragedy.