What was the prime reason why Russia became increasingly separated from the rest of Europe during the 13^th century?

Question

Quizplus · Accepted Answer

The invasion by the Mongols in the 13th century led to the devastation of many of the major cities in Russia, including Kiev. This led to a period of isolation as Russia fell under Mongol control and was cut off from much of the rest of Europe. This period of isolation continued even after the Mongols were driven out, as Russia remained largely independent from the rest of Europe until the reign of Peter the Great in the 18th century.

What Was the Prime Reason Why Russia Became Increasingly Separated