However, due to his age, his uncle Prince Aribert of Anhalt was appointed regent.

[1] Later he became a critic of Nazi rule, and in winter 1944 was arrested and spent three months in the Dachau concentration camp.

He welcomed the overthrow of Nazi rule, and remained in the Soviet occupation zone in Germany, believing that his record as an anti-Nazi would protect him, but on 31 August 1945 he was arrested by the NKVD during a general round up of 'Junkers' or Prussian landed gentry.

[3][4] In Ballenstedt Castle on 3 March 1927, Joachim Ernst married firstly Elisabeth Strickrodt (Plauen, 3 September 1903 – Berlin-Zehlendorf, 5 January 1971), a daughter of an opera singer.

[citation needed] In Ballenstedt Castle on 15 October 1929, Joachim Ernst married secondly Editha "Edda" Charlotte Wilhelmine Marwitz von Stephani (Düsseldorf, 20 August 1905 – Garmisch-Partenkirchen, 22 February 1986), natural daughter of Wilhelm Horn by Irmgard Klara Franziska Marwitz.