[2] He joined the Communist Party of Germany and Rote Hilfe, German affiliate of the International Red Aid, in 1931.
[3] He served as the state secretary at the Ministry of Heavy Industry in East Berlin between 1950 and 1951.
[2] Gregor was appointed minister for foreign and inner German trade in September 1952, succeeding Georg Handke in the post.
[6] Heinrich Rau was appointed minister for foreign and inner German trade in April 1955.
[4] He was a member of the East German Parliament from 1958 to 1963 and was the deputy secretary of the Council for Mutual Economic Assistance in Moscow.