I think a useful example is in the book "How the Irish Saved Civilization." The basic premise is that Christian monasteries isolated from the post-Roman disorder preserved knowledge and knowledge tradition that reemerged later. Stating this is not intended as unqualified praise for the book or to deny the role of Orthodox, Syriac and Islam in knowledge preservation or to say that the deconstruction of the Roman Empire was a bad thing.

https://en.wikipedia.org/wiki/How_the_Irish_Saved_Civilizati...