In 1945, as Soviet forces were attacking, he resisted pressure from the Nazi government to leave Breslau, until much of the population was evacuated. Bertram finally decided to leave the city in late February or early March 1945 and spent the rest of the war at his summer residence at Castle Johannesberg in Jauernig (Czechoslovak part of Breslau diocese, Sudetenland), where he died on 6 July 1945 at the age of 86.