Rudolf Margolius was born in Prague into a patriotic Czech, middle-class milieu. As a law student in the thirties at Charles University, studying together with the Czech poet Hanuš Bonn, he devoted much of his time to the YMCA travelling in Western Europe, Middle East and America. During Czechoslovakia’s Munich crisis with Nazi Germany he was an Army reservist serving together with his friend, music composer, Jan Hanuš. In 1939, while Czechoslovakia was already occupied by the Third Reich, he married Heda Bloch (later known as Heda Margolius Kovály).