This is the first general study in English on the German Expressionist writer Walter Hasenclever (1890-1940) and the first that draws upon new materials found in his collected works, which were completed in 1997. It draws additionally on the author's archival research in eastern Germany. Spreizer's work deals with the life and writings of this major figure in the Expressionist literary movement, first known for his volume of Expressionist poetry Der Jungling (1913), and best known today for his groundbreaking Expressionist drama Der Sohn (1914). Hasenclever was active in the literary life of the Weimar Republic, carrying on a lively correspondence with the publisher Kurt Wolff and the literary critic Kurt Pinthus and other prominent figures of the period. Critical of the Nazis in his plays and articles, Hasenclever was denounced and his works later burned upon the Nazi seizure of power. After 1933, he lived in exile in Italy. England, and France, writing plays and two autobiographical novels. He committed suicide in French internment in 1940 upon the German invasion of France.