This you Poles needs to know.
When we all failed and betrayed our ancestors Gods, Nemanjic Dynasty raised in Serbia and restored the spiritual balance, refusing the dictate from both- the Roman and Constantinople global trade guilds.
We know for certainty for a three dynasties that ruled Serbian lands before Nemannjic dynasty. Svevladović (490. do 641. AD), Svetimirović (641. do 794. AD) and Oštrivojević (724. do 1171. AD). They all let Rome and Constantinople Christianize the Serbs (and influenced all other Slavs, Poland included) without any control. Most of Serbs that were Christians back then were Catholics.
Then, Nemanjic dynasty came to be. The richest medieval dynasty that ever ruled anywhere in Europe.
Nemanjic`s had enormous influence on Polish Piasts and influenced raise of Jalilonian dynasty. Nemnjic`s Catholics themselves, came in conflict with the Pope`s dictate. Nemanjic`s were able to note and react to the lines of wealth flow that are directed thanks to Churches. Wealth lines that led to the papacy. Then, they noticed similar lines of wealth flow to sate Constantinople. But, Constantinople was weaker. Nemanjic`s then cut off the papacy, took the Orthodoxy but created Serbian national (peoples) Church. Spiritual lines and lines of wealth needs to exist in balance, with focuses in our land, if people is to be free, remarked Sava Nemanjic (Rastko Nemanjic, the youngest son of Veliki Zupan Stefan Nemanja). It was kind of Protestantism long before official era of Protestantism (except Serbian Orthodoxy was in line with original codes of the Christian Church, holly trinity and Mother of Christ).
Finally, to cement the national being of the Church youngest son of Veliki Zupan, suggested the preservation of ancestral cult within Christianity and since then ancient common Slavic custom SLAVA function legally for all the Serbs.
SLAVA is the Serbian spiritual gift to the future generations of all Slavs. That is the result of our spiritual battle with Rome and Constantinople who wanted to take our soul.