What was the biggest change in the world following the end of the Roman Empire?

The biggest thing that was a result of the end of the Roman Empire was the emergence of feudalistic kingdoms and states that seemed to appear independently. I am particularly referring to Europe but it could also be used to refer to the Middle East as well. <br><br>However, I am currently studying the Tang and Ming dynasties in China and I am also learning about the rise of the Japanese Shogunate during this time. It seems like the emergence of these societies weren't necessarily influenced by the collapse of the Roman Empire, which seems strange since they did have some interaction and semi-diplomatic relations with Europe following the end of the Roman Empire.<br><br>So, the question is, what was the biggest change in the world after the collapse of the Roman Empire, and how did the collapse of the Roman Empire impact Asian societies?