Nazi persecution of the Catholic Church in Poland

 It is less understood that due to their ethnic identity that approximately, 1. 9 million Polish Catholic citizens were murdered during the Holocaust and that 1.7 million Polish non-Jews were imprisoned in concentration camps in Siberia, 2.0 million were deported as forced laborers for the German Reich and 100,000 were killed in Auschwitz. 

https://aura.antioch.edu/cgi/viewcontent.cgi?article=1030&context=etds#:~:text=Between%20the%20years%20of%201939,Catholics%20were%20killed%20in%20Auschwitz.

https://en.wikipedia.org/wiki/Nazi_persecution_of_the_Catholic_Church_in_Poland