Abstract

The categorical rejection of the Ferrara-Florence Union by the Moscow leadership, as sometimes restrained, is sometimes unconcerned, but in general, the positive attitude towards the communist act of unification of the Orthodox and Catholic Churches from the side of the ruling circles of the Commonwealth is a fact that is undeniable and scientifically irrefutable. However, not all of those who have been guarding the ideological support for this self-evident nature for more than half a century are prepared to take into account the positional distinction that touches the intra-Orthodox sphere. Therefore, I would like to present an account of the explanation of the factors that brought about the theory of "Moscow - III Rome" to life, and also led to the emergence of "Letters of Misail".