With the collapse of the Roman Empire, migration was again mostly coupled with warlike invasion, not least during the so-called Migration period (Germanic migrations), the Slavic migrations, the Hungarian conquest of the Carpathian Basin, the Islamic conquests and the Turkic expansion into Eastern Europe (Kipchaks, Tatars, Cumans).
There were substantial population movements within Europe throughout the Early Modern period, mostly in the context of the Reformation and the European wars of religion, and again as a result of World War II.