I agree it was a time of isolation. Christianity was spreading to China and North Africa from 100-600 A.D. before Islam shut it down for 1000 years. Imagine how many souls were lost because of Islam.
In the 1500s, the Catholic church baptized 10 million souls to Christ in Mexico. Praise God. The British had the Masons, which persecuted the Church greatly for the next few centuries.
Thanks for exchanging thoughts on history and Christ. It is a shame that so much knowledge has been lost.