Ostsiedlung (, literally
east settling), also called
German eastward expansion, was the medieval eastward migration and settlement of
German speakers from the
Holy Roman Empire (primarily present-day southern and western
Germany) into less-populated regions of eastern
Central Europe. The affected area roughly stretched from
Slovenia to
Estonia, and southwards into
Transylvania. In part,
Ostsiedlung followed the territorial expansion of the Empire and the
Teutonic Order.