Career
From 1912 he was Director-General of the Essener Steinkohlenbergwerke AG and Chief Executive Officer of Gelsenkirchener Bergwerks-AG. In addition to Carl Hold and Gustav Knepper he was one of the most influential mining figures in 1930s Ruhr Valley.
Politics
Nazi Party, German People"s Party.
Membership
In the 1920s Tengelmann was an active member of the German People"s Party, but in 1930 he joined the Nazi party and participated in the Secret Meeting of 20 February 1933 where he gave the party considerable financial support.