On its publication in October 1940, Ernest Hemingway’s For Whom the Bell Tolls was widely acclaimed but caused anger and dismay among supporters of the defeated Spanish Republic, starting with veterans of the Abraham Lincoln Brigade. For them, the most egregious passage in the novel was Hemingway’s portrayal of André Marty, chief political commissar of the International Brigades, as a bloodthirsty ‘crazy’: ‘está loco’, say all those who encounter him. This article places the reception of the novel and the reputation of Marty in the context of the tortuous history of the communist movement. Drawing on the press, memoirs, historiography and Marty’s own private papers, we see how the contrasting fortunes of the novelist and the communist leade...