The Silk Road, which has been understood as a generalized route of trade between the East and the West, is different from European, North African, and Near Eastern trade routes because until recently, it has been understood as solely being a land route; in fact, it was believed to be the longest overland trade route in human history. The history of the Silk Road is extremely complex. It cannot be told as a singular chronological narrative. Different cultures and societies rose and vanished along the Silk Road, and peoples migrated from one region to another. In short, for most of its history, there was fluidity as to the dominant cultures along the route or routes. Explaining the rise and fall or disappearance of these cultures involves stopping along the way to consider the chronology of their histories.