A short history on migration

The unpleasant and unadmitted story of migration is that every time someone builds a civilization, the barbarians flock to it to destroy it.

WE've been dealing with it for roughly 6500 years and that isn't counting the Cro Magnons. Aryans Goths Huns Gepids Avars Slavs Bulgarians Longobardians Hungarians Pecenegs Cumans Arabs Tatars Turks Gipsies ...