Silesia refers to the land northeast of the Sudetes Mountains, around the upper and middle reaches of the Oder River.

Prussia acquired most of Silesia from Austria under Frederick the Great during the mid-18th century. Compared to East and West Prussia, a sharper ethnic divide between Germans and Poles is evident, that is more similar to the linguistic situation in Bohemia and Moravia than the more blended situation of the other eastern Prussian provinces.

German speakers predominated in Lower Silesia, forming a largely homogeneous population. Those in the north tended to be Lutheran, while those in the south nearer to Bohemia were Catholic.

Sorbian speakers lived in the far west, between Brandenburg and Saxony (where they were also found in great numbers).

Czech speakers could be found in the far western Glatzer Land (the "Czech Corner") and in the Hultschin Land in the south. Additionally, communities of Czech speakers, descended from Protestant Moravian Brethren who had left Catholic Habsburg lands in exile, could be found in a few scattered settlements (the largest of these being Hussinetz, so named after Jan Hus).

Polish speakers (most of whom spoke the Silesian dialect which unfortunately was not distinguished from Polish in the Prussian census) predominated in the southeast, with the exception of larger towns/cities where in many cases German speakers were (often narrowly) the majority.

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Physical: https://commons.wikimedia.org/wiki/File:Silesia_Physical_Map.png

Linguistic: https://commons.wikimedia.org/wiki/File:Silesia_Language_Map_1905.png