In his new book, Stormtroopers: A New History of Hitler’s Brownshirts (Yale University Press, 2017, Daniel Siemens, professor of European history at Newcastle University, writes a comprehensive history of the SA, from the early 1920s until Nazi Germany’s total defeat in 1945. Siemens demonstrates how the SA evolved from a small organization to a massive and potent force that directly impacted the Nazi rise to power, and how that organization shaped German society during the Nazi period. He tackles the long-held view that the SA had become largely irreverent after the 1934 purge known as the “Night of the Long Knives,” and shows how the SA had significant impact in the military, the management of conquered territories and the Holocaust.