The affected area roughly stretched from Slovenia in the south to Estonia in the north, and extended into Transylvania in the southeast. In part, Ostsiedlung followed the expansion of the Empire. German historians of the nineteenth and twentieth centuries often exaggerated the importance of the adoption of Salic law and settlement in Central, thus Ostsiedlung is part of a process termed Ostkolonisation or Hochmittelalterlicher Landesausbau, although these terms are sometimes used synonymously. Ethnic conflicts erupted between the newly arrived settlers and local populations and expulsions of native populations are known of. In several areas subject to the Ostsiedlung, the population was later discriminated against. Central Europe underwent dramatic changes after the Migration period of 300 to 700 CE, the Roman Empire had lost its dominant position. The Franks had created an empire that, besides former Roman Gallia, had united the former West Germanic tribes, East Francia, an early predecessor of Germany, aimed to be the successor to the Christian Western Roman Empire, and developed into the Holy Roman Empire. In Scandinavia, the former North Germanic tribes entered the Viking Age, affecting the whole of Europe through trade, some former East Germanic tribes had entered and merged into Rome, their own culture ceasing to exist. The Slavs living within the reach of the Frankish Empire were collectively called Wends and they seldom formed larger political entities, but rather constituted various small tribes, dwelling as far west as to a line from the Eastern Alps and Bohemia to the Saale and Elbe rivers. As the Frankish Empire expanded, various Wendish tribes were conquered or allied with the Franks, such as the Obodrites, the conquered Wendish areas were organized by the Franks into marches, which were administered by an entrusted noble who collected the tribute, reinforced by military units. The establishing of marches was also accompanied by missionary efforts, Frankish kings initiated numerous, yet not always successful, military campaigns to maintain their authority. Weakened by ongoing conflicts and constant warfare, the independent Wendish territories finally lost the capacity to provide effective military resistance. From 1119 to 1123, Pomerania invaded and subdued the northeastern parts of the Liutizian lands, in 1124 and 1128, the Pomeranian duke Wartislaw I, at that time a vassal of Poland, invited bishop Otto von Bamberg to Christianize the Pomeranians and Liutizians of his duchy. In 1147, as a campaign of the Northern Crusade, the Wendish Crusade was mounted in the Duchy of Saxony to retake the marches lost in 983, the crusaders also headed for Pomeranian Demmin and Stettin, despite these areas having already been successfully Christianized. The Havelberg bishopric was set up again to Christianize the Wends, after Henry the Lion lost an internal struggle with Emperor Frederick I, Mecklenburg and Pomerania became part of the Holy Roman Empire in 1181. Terra Mariana was the name for Medieval Livonia or Old Livonia which was formed in the aftermath of the Livonian Crusade in the territories comprising present day Estonia and Latvia. It was established on February 2,1207 as a principality of the Holy Roman Empire, the nominal head of Terra Mariana as well as the city of Riga was the Archbishop of Riga as the apex of the ecclesiastical hierarchy. In 1561, during the Livonian war, Terra Mariana ceased to exist, the island of Saaremaa became part of Denmark
Phases of German eastward expansion according to Walter Kuhn
West-Slavic peoples in Europe until 1125 (yellow borders). Prussia (identified as Pruzzia) has not been a Slavic land.
Vilamovians (West Germans), Wilamowice
"German" dialects in central Europe, 1894 (here including other West Germanic languages: Low German and Dutch, but excluding Frisian)