How can one best explain the emergence of Western Europe as a dynamic civilization after 1000 C.E.?

It's been a long time since I had a history class, but I believe it was due to the fall of Rome that led to the rise of feudalism. I don't know that I'd call the dark age feudal system a dynamic civilization, but certainly it's rigid hierarchies contributed to the rise of the monarchies that unified the many small kingdoms into large nations. This unifying may have allowed greater ease for travel and a resulting spread of knowledge, as fewer kingdoms meant fewer difficulties and negotiations to travel safely.