[Ger-Poland-Volhynia] Germans in Czech Republic?

[Stacy Flatt]

Just a very general question -

I'm curious... were there any German settlements in what is now the Czech
Republic?  If so, what happened to those settlements?  Are there ethnic
Germans still living there now or did they mostly migrate out?

Specifically, in case anyone has specific info, my ancestors are largely
Flatt, Seib, Masschenski (various spellings) Fergin, Reshke, Schmidt,
Strohscein, Fergin, and Pflueger.  They also tended to hang around the Rapp
family a lot.  I can trace them to various parts of Poland and western
Ukraine.

Thank you!
Stacy