Complex sentence: Gregor Schwartz-Bostunitsch (December 1 1883--unknown) was a prominent figure in Nazi Germany, he was an German-Ukrainian author of the Völkisch movement and became SS-Standartenführer in 1944.
Split into simpler sentences: Gregor Schwartz-Bostunitsch (December 1 1883--unknown) was a prominent figure in Nazi Germany. He was a German-Ukrainian author in the völkisch movement and became SS-Standartenführer in 1944.