Holocaust victims
In 1942, Dutch bishops protested the mistreatment of the Jews. When the Dutch Archbishop refused to obey the Nazis, the Gestapo rounded up Catholic "Jews" and sent 92 to Auschwitz  A Dutch Catholic nun named Edith Stein was murdered at Auschwitz.  So was Maximilian Kolbe, a Polish priest.  Both were eventually made into Catholic saints by Pope John Paul II in the 1980s.  Other Catholic victims of the Holocaust have also been beatified, including some of the Polish priests who died at Dachau.