Medieval German eastward settlement later armed nationalist myths
Ostsiedlung names early and high medieval migration of Germans into Slavic, Baltic, and Uralic lands—Germania Slavica. Princes invited settlers; sometimes prior inhabitants were pushed aside. Twentieth-century nationalists, including Nazis, weaponised the story until postwar expulsions reversed German speech east of the Oder.
Small early medieval moves preceded larger twelfth-century treks of scholars, monks, missionaries, and artisans, often invited, numbers unverifiable. After 1944–1950, Germans were driven from reduced postwar borders, erasing language communities the migration had planted.
Migration Period background saw Germanic elites take Roman south while Slavs filled emptied eastern zones—setting the board Ostsiedlung later replayed in reverse cultural direction.
The groundwork was Carolingian. Charlemagne ringed his eastern frontier with marches, among them a Danish March near the Danevirke, a Saxon march between the Eider and the Elbe facing the Obotrites, a Sorbian march on the Saale, and an Avar frontier reaching from the Enns to the edge of Vienna's woods, the earliest planned eastern policy on record. The peoples inside these marches made unreliable allies, and later kings campaigned again and again, not always successfully, to hold them. In 843 the empire split three ways after Charlemagne's grandsons quarrelled over partible inheritance versus primogeniture. Louis the German took East Francia, and under him and Arnulf of Carinthia the first Catholic civilian settlers, led by Franks and Bavarians, moved into Pannonia, today's Burgenland, Hungary, Slovakia and Slovenia. Punitive wars then won broad territories stretching from the Elbe, Saale and Naab on one side to rivers such as the Oder, Bober, Kwisa and Vltava on the other, secured by new border marches and forts. Most later settlers, though, came individually and in successive waves.
Source: Ostsiedlung
