The International Brigades: Fascism, Freedom and the Spanish Civil War, by Giles Tremlett. 696 pp. London: Bloomsbury. $30.

Consider the obstacles faced by the volunteers from around the world who rushed to help defend Madrid in the perilous autumn of 1936, when Franco’s Nationalists almost captured the city. An order might come from brigade headquarters in German, be passed on in Serbo-Croatian, and be incomprehensible to an infantryman who spoke only French. Furthermore, that volunteer may have been issued unreliable ammunition for his rifle, from which he had the chance to fire only a few shots in hasty training, and then come under friendly fire from malfunctioning artillery shells that fell short. And all this when facing an army equipped with a flood of weaponry from Mussolini and Hitler. But the International Brigades troops fought on nonetheless.

They came from 65 countries all told, according to Giles Tremlett, the Guardian correspondent in Spain and author of this authoritative new study. He estimates that at least 20% gave their lives. The first members to leave for the front received their rifles only two days before, and the first seven to die were “four Hungarians, a Greek, a Yugoslav and one of a number of volunteers who were deemed ‘stateless.’” Most likely, they did not all have a language in common.

Before Tremlett’s welcome book, there had been no full-length, unbiased history in English of this extraordinary facet of the Spanish Civil War: the roughly 35,000 volunteers from across the globe who came to Spain to defend its democratically-elected government. Tremlett makes use of a vast array of material, including some from the Nationalist side; his source notes and bibliography alone run to 124 pages, a rich resource for future scholars.

Tremlett gives us the Brigades warts and all: he does not stint in describing the incompetent, the paranoid, and the martinets among their commanders, from the notorious André Marty on down; or the shooting of prisoners and deserters; or the way so many Brigade veterans ended up in key positions in the repressive postwar regimes of Eastern Europe. I did not previously know, for instance, that Brigade vets commanded the Stasi, the East German secret police, for almost all of its existence. It’s a sobering reminder of the mixture of loyalties that brought people to Spain, and of the way a person who plays a heroic role at one point in history can play a thoroughly unsavory one a decade or two later. We’ve seen reminders of that recently, in the lives of people like Jacob Zuma in South Africa or Daw Aung San Suu Kyi in Myanmar.

Nonetheless, this is still an inspiring story, especially for the world we are living in now, with authoritarian strongmen on the rise on nearly every continent, and a recent narrow escape from being fated to have four more years of an odious one of our own. Even though they failed in the end, the volunteers of 1936 had a sense of international solidarity in fighting against these sinister forces that has no exact parallel in our own time.

The International Brigades is not always an easy book to read. Conscientious about telling almost every facet of the story, Tremlett floods the reader with a dense cascade of names—of commanders, units, foot soldiers. It is something of a relief when he threads through several late chapters the poignant story of the British volunteers Nan Green, a nurse, and her doomed husband George, taken from her memoir and Paul Preston’s excellent book of portraits, Doves of War: Four Women of Spain.

Tremlett’s account is, inevitably, even more complicated because Spanish soldiers were integrated into the Brigades as the war went on. He includes useful tables of the numbers of foreign volunteers and where they came from, but the book could have greatly benefited from a multipage chart showing the five International Brigades, their constituent battalions, their commanders, and how these changed over time. Also, Tremlett has not been well served by his publisher in the book’s maps, which sometimes show towns and cities not referred to in his text, and all too often don’t show towns, rivers, mountain ranges, and regions of Spain which are mentioned. One map even shows a section of the front line without indicating which army is on which side. I hope these things will be corrected in a later edition.

This is a book for someone who already has a good grasp of the Spanish Civil War, such as can be had from one of the thorough overall histories by Preston, Hugh Thomas, or Antony Beevor. Tremlett assumes you know the basics about the causes of the war and the alignment of forces behind the Republicans and Nationalists. He does not really pull his camera back to provide a wider view of world politics until the withdrawal of the Brigades from combat in late 1938, against the background of the appeasement of Hitler, the Munich agreement, and the descent of Europe towards the wider war that would begin only months after the one in Spain ended.

As a comprehensive history, The International Brigades is a good corrective for English-speaking readers, since all too often our knowledge of the war comes from books by or about the American, British, and Canadian volunteers. But all Anglophones together were only a small proportion of the Internationals, less than one in six. And none were refugees from fascism, as was the case with German and Italian volunteers and many of those from Eastern Europe. The “Italian Civil War” between Mussolini’s Italians and Internationals who included many Italian volunteers on the battlefield at Guadalajara in early 1937 was great fodder for correspondents at the time. But one of the many memorable vignettes Tremlett has unearthed is of German volunteers at the battle of Brunete the same year, engaged in a nighttime shouting match of insults with Germans in the Nationalist trenches. It is a reminder that Spain was not the only divided country at this time; in one way or another, most of Europe had similar fissures. And indeed, so did much of the world. Jawaharlal Nehru, who visited the “gallant men” of the British battalion, saw in their commitment an echo of his own in the long battle for Indian independence.

More than anything else, this book is a reminder of the tremendous odds against which the Internationals fought. They sometimes had to dig trenches with helmets and bayonets when there were no shovels. In the long retreat in the spring of 1938, when they ran out of grenades the desperate volunteers pelted the enemy with rocks. They all too often could only wield weapons dating from before the First World War, while from the skies they were attacked by Hitler’s newest Messerschmitt Bf 109 fighters or Stuka dive-bombers. And even some veterans who survived would face, after the war, concentration camps in France, death in Stalin’s purges, or blacklisting in the United States and some other countries. Yet few survivors regretted that they had gone. I remember, more than 50 years ago, meeting an American vet, George Draper, and asking how he looked back on the war. He began by saying, simply, “I wish we’d won.”

Adam Hochschild is a member of ALBA’s Honorary Board and is the author of ten books, including Spain in Our Hearts: Americans in the Spanish Civil War, 1936-1939.