[Katya]

Silesians speak german, czech or polish...depending on which country they live in. Prussian was spoken in the regions of Masuria, Silesian I seem to remember was a part of Bohemia.

[Amberdawn]

OK, Thanks to both Tallguy and you, Katya.

[Verginius Rufus]

Silesia belonged to Austria until 1740. On the death of Charles VI, when Maria Theresa inherited the throne, Frederick II invaded Silesia and touched off the War of the Austrian Succession. Maria Theresa managed to hold on to her other possessions but finally had to give up on regaining Silesia (at most she may have kept a very small piece of it).

I think it was mainly German-speaking until 1945 but the Germans were forced out when the western border of Poland was set at the Oder-Neisse line.