Josef Breitenbach was born into a middle-class wine-merchant Jewish family, and came of age during the chaotic years of the First World War and its troubled aftermath. He attended technical high school from 1912–15 and trained as a salesman for an instrument firm and later as a bookkeeper for an insurance firm. He attended Ludwig-Maximillian University in Munich (philosophy and art history, 1914 to 1917) and became active in the Youth Section and later the Pacifist wing of the Social Democratic Party. In 1918, he took part in the Soviet-inspired Bavarian coup d’état, which was the first spark of the revolutionary fire that swept over Germany in the wake of the armistice. For a few months, Breitenbach also occupied an official position in the new government. Although the revolution was short-lived, the ties he forged with the radical circles of Munich’s intelligentsia later helped him establish his reputation as a photographer.