Hans was born to Jewish parents in a town in northwestern Germany. The family moved to Berlin when Hans' father obtained a post there as a history teacher in a secondary school. After graduating from university, Hans married and settled with his wife Margaret in an apartment in Berlin. In 1920 their child Wolfgang was born. Hans worked as foreign representative for a sewing notions company.

1933-39: When the Nazis won the election a few weeks ago, I was afraid for people like me who are active members of the socialist party. I was right. Someone has just slipped a note under our door with a warning: The Nazis are rounding up socialists, and, as the local district supervisor for the Social Democratic Party, I'm on their list. We're going to leave in a hurry and try to sublet a room under an assumed name in another neighborhood.