Heinrich Loewenwarter was born in Cologne on the Rhine on December 1, 1871, the son of David Loewenwarter and his wife Emma, née Grünenbaum. He became a merchant and married Valentine Wanda Bartkowiak, a saleswoman, in Berlin on October 27, 1909.

Edith Löwenstein was born on July 19, 1903 in Berlin into a Jewish family; she also had an older sister Else.