Sorbs traditionally speak the Sorbian languages also known as "Wendish" and "Lusatian" , which are closely related to Czech and Lechitic languages. Upper Sorbian and Lower Sorbian are officially recognized minority languages in Germany. From the High Middle Ages , they were ruled at various times by the closely related Poles and Czechs , as well as the more distant Germans and Hungarians.
Due to a gradual and increasing assimilation between the 17th and 20th centuries, virtually all Sorbs also spoke German by the early 20th century. In the newly created German nation state of the late 19th and early 20th centuries, policies were implemented in an effort to Germanize the Sorbs. These policies reached their climax under the Nazi regime, who denied the existence of the Sorbs as a distinct Slavic people by referring to them as "Sorbian-speaking Germans". The community is divided religiously between Roman Catholicism the majority and Lutheranism.
The original ethnonym, Srbi , was retained by the Sorbs and Serbs in the Balkans. The name of the Sorbs can be traced to the 6th century or earlier when Vibius Sequester recorded Cervetiis living on the other part of the river Elbe which divided them from the Suevi Albis Germaniae Suevos a Cerveciis dividiit. The Saale-Elbe line marked the approximate limit of Slavic westward migration. According to a 10th-century source De Administrando Imperio , they lived "since the beginning" in the region called by them as Boiki which was a neighbor to Francia, and when two brothers succeeded their father, one of them migrated with half of the people to the Balkans during the rule of Heraclius in the first half of the 7th century.
The two groups were separated from each other by a wide and uninhabited forest range, one around Upper Spree and the rest between the Elbe and Saale. In , Sorbian Duke Czimislav was killed.
Gero , Margrave of the Saxon Eastern March, reconquered Lusatia the following year and, in , murdered 30 Sorbian princes during a feast. A reconstructed castle, at Raddusch in Lower Lusatia, is the sole physical remnant from this early period. Following the subsequent German—Polish War of — , the Peace of Bautzen confirmed Lusatia as part of Poland; but, it returned to German rule in In the s, southern Lusatia, passed into the hands of the Sorbs' other Slavic relatives, the Czechs, within their Duchy of Bohemia.
