Conversation so far:
What did Erich Honecker do to oppose the Nazis?
In 1930, Erich Honecker entered the KPD, the Communist Party of Germany. He later worked closely together with then-KPD official Herbert Wehner in opposition/resistance to the Nazi state.
Why was Erich Honecker imprisoned?
On 3 July 1937 Erich Honecker was sentenced to ten years imprisonment for the preparation of high treason alongside the severe falsification of documents.

Question: When was he released?
Self-contained rewrite: When was  Erich Honecker released?