Mosse was born in Berlin into one of Germany's richest Jewish families, where his maternal grandfather, Rudolf Mosse, was the founder of one of Germany's leading newspaper concerns and publisher of "Berliner Tageblatt".
Mosse was born in Berlin into one of Germany's richest Jewish families. His maternal grandfather was the founder of one of Germany's leading newspaper concerns. His maternal grandfather was the founder of one of publisher of "Berliner Tageblatt". Rudolf Mosse was his maternal grandfather.