Complex sentence: On his arrival, he was appointed to the Judenrat, until then under the general direction of Jakob Edelstein, who was deported to Auschwitz in December 1943, and in June 1944 being forced to stand by and witness the gunning down of his wife and son.
Split into simpler sentences: On his arrival, he was appointed to the Judenrat, which until then under the general direction of Jakob Edelstein, who was deported to Auschwitz in December 1943. In June 1944, he was forced to stand by and witness the gunning down of his wife and son.