Paul Engel was born into a middle-class Jewish family on May 4, 1922 in Vienna, Austria. He had a younger brother, Robert. When World War I broke out in 1914, his father, Eduard, was drafted into the Austro-Hungarian army. Captured as a prisoner of war, he spent six years in Siberia working in a coal mine, finally reuniting with his family in 1920. In Vienna, Eduard owned a perfume wholesale business. Before the war, Paul attended a primary school and was accepted to a Gymnasium in the 14th district of Vienna.