The Saxons themselves were interlopers who originally came from what is now Germany.
They, in turn, were victimized by interlopers from Normandy, who were the 3rd and 4th generations of viking invaders from Scandinavia that had successfully blackmailed the French out of some of their land.
The Scandinavian vikings probably came from what is now Finland and Russia which were, in turn, populated by invaders who came from the south and east of the areas located around the Black Sea and Turkish peninsula.