Complex sentence: The fighters only learned the man's identity through the German press: it was General, the assistant in France to Fritz Sauckel, who was responsible for the mobilization and deportation of labor under the German STO (Obligatory Work Service) in Nazi-occupied Europe.
Split into simpler sentences: The fighters only learned the man's identity through the German press. It was General, the assistant in France to Fritz Sauckel, who was responsible for the mobilization and deportation of labor under the German STO (Obligatory Work Service) in Nazi-occupied Europe.