As the Roman Empire and Christianity spread to the north of Europe, the most important places of worship were turned into churches.

Yes, it is. In Russia, more precisely, in Russia, there was a Vedic faith (it is incorrectly called pagan). In most places where Christian churches now stand, there were Vedic temples and sacred groves.
Grand Duke George Mikhailovich... I know about the current of the monarchists and their attempts to claim something in Russia. I think that for the money that was paid for the opportunity to hold a wedding ceremony there... he could get married in any other place of his choice. "Whatever the child is not amused, just not to get pregnant" - we have such a proverb and in my opinion it is suitable for this situation)