Ernst became the only former reigning German prince who accepted German Democratic Republic citizenship after World War II, refusing an offer to leave his beloved "Palace of Happy Returning" and relocate to the British occupation zone. The Schloß had been confiscated by the Soviet occupiers, but Ernst had been granted free use of it until his death. In March 1954, with the death of Charles Edward, Duke of Saxe-Coburg and Gotha, he became the last survivor of the German princes who had reigned until 1918. One year later, he died at the Schloß.