Trepp recalled having conducted his first seder in 1936 in Oldenburg, when he was a newly ordained rabbi in Nazi Germany, leading the 15 synagogues in the district.
[4] He saw that he had a dual role in working "to keep the Jewish community from breaking down, while at the same time give many fellow believers the possibility to emigrate".
[1] He recalled the inmates being called out in Sachsenhausen at 4:00 in the morning, seeing the guard towers manned with soldiers holding machine guns and being told "You are the dregs of humanity.
"[1] Trepp was released from Sachsenhausen after 18 days of incarceration through the intervention of Joseph Herman Hertz, the Chief Rabbi of the United Kingdom—under the condition that he and his wife had two weeks to leave the country.
[6] Despite his longstanding efforts at fostering Christian–Jewish reconciliation, Trepp expressed concern that in the hands of nationalists and Islamists that "Anti-Semitism has become acceptable again".
"[7] Trepp was the subject of the 2009 German language documentary film Der Letzte Rabbiner by Christian Walther, which was translated into English and shown as The Last Rabbi.