Kurt Held was the pen name of Kurt Kläber, born to a Jewish family in Germany. He left school at age 14 and trained as a locksmith and as a mechanic at Zeiss. He traveled through Europe before World War I, when he fought with the German Army. After the war, he joined the Communist Party of Germany (KPD) and took part in violent demonstrations in Halle, Hamburg, and Berlin. He published his first work, a volume of poetry called Neue Saat (New Seed), in 1919. In 1923 he spent a year traveling and giving lectures in the USA, studying the lives of workers there, which provided material for his first novel, Passagiere der III. Klasse (Third Class Passengers, 1927). In 1924, he married fellow writer Lisa Tetzner. He edited and published a journal for workers called Linkskurve. When the Nazis seized power, they arrested and imprisoned him. With his wife's help, he was released, and the couple fled into exile in Switzerland.
He left the Communist Party in 1938 in reaction to Stalin's Great Terror. With Tetzner, he co-authored the nine-volume series The Children from No. 67 (1933-1949), and other books. His best known solo work was The Outsiders of Uskoken Castle (1941).