Complex sentence: During the German occupation Goldschmidt was arrested, on account of him being of Jewish extraction, but released by initiative of colleagues and the Norwegian Resistance shortly before his planned deportation to a German concentration camp.
Split into simpler sentences: During the German occupation Goldschmidt was arrested, due to being of Jewish extraction. However, he was freed at the initiative of his colleagues and the Norwegian Resistance shortly before a planned deportation to a German concentration camp.