The Spanish Civil War came to an end on April 1, 1939, just days after Francisco Franco’s Nationalist troops entered Madrid. By the time the capital fell, following a long siege, the war’s body count had reached nearly half a million. About one hundred fifty thousand of those deaths directly owed to the Francoist terror; a further twenty thousand Republican prisoners were executed in the immediate wake of the Nationalists’ victory. Thousands more died in concentration camps across the country or in refugee camps over the border in southern France.

Renowned historian Paul Preston called it the “Spanish Holocaust.” Now, eighty-five years after the defeat of Spain’s democratic Second Republic, Preston’s new book turns the spotlight on Britain’s crucial but often overlooked involvement in the Spanish war. It explains how the British and French governments’ so-called policy of nonintervention — as per a diplomatic agreement with Nazi Germany, Fascist Italy, and the Soviet Union — hobbled the Republican war effort. As Preston argues in Perfidious Albion: Britain and the Spanish Civil War, London’s position was not just a policy of abstention, but of siding with the rebels:

Most commentators have placed considerable weight on the logistical assistance given to Franco by Hitler and Mussolini. However, the bald statement that Franco’s military rebels enjoyed a massive advantage thanks to the support of Nazi Germany and Fascist Italy fails to take into account the considerable advantage provided by the barely disguised sympathy of the Conservative government of Great Britain. . . .  The democratic powers of Western Europe ignored any considerations of self-interest, let alone of solidarity when they effectively supported the cause of the Spanish military rebels behind the farcical façade of non-intervention