KL: A History of the Nazi Concentration Campsby Nikolaus WachsmannFarrar, Straus and Giroux, 2015It's entirely possible for a book as somber and monumental as Nikolaus Wachsmann's new KL: A History of the Nazi Concentration Camps to be both definitive and boring. The subject of the Holocaust and the Nazis' attempted genocide of European Jewry has been told many thousands of times since the end of the Second World War, and the libraries of volumes that have resulted contain definitive books that are both horrifying in their contents and grindingly boring in their execution. Wachsmann's dozens and dozens of pages of sources amply demonstration that he's read all those horrifying yet boring books; he's clearly scrutinized countless document, countless timetables and inventories, countless memoirs and courtroom testimonies. From all this he's produced his enormous book, the first systematic study of the entire system of Konzentrationslager, or KL, the vast network of twenty-seven main Nazi concentration camps and over 1000 smaller satellite camps that dotted Nazi territories in Germany, Poland, France, Czechoslovakia, Lithuania, Belgium, the Netherlands, Austria, and even Alderney Island in the British Channel.KL is certainly definitive, but it's much to Wachsmann's credit that in addition to being somber and monumental, his book is also intensely readable. It's tidings are utterly appalling, but it works beautifully as a book. Wachsmann tells his terrible stories with a cold and unflagging skill.He begins by making a now-necessary distinction, differing the huge and complicated system he intends to describe from its most famous avatar:

Auschwitz was never synonymous with the Nazi concentration camps. True, as the largest and most lethal camp by far, it occupied a special place in the KL system. But there was always more to this system. Auschwitz was closely integrated into the wider KL network, and it was preceded and shaped by other camps. Dachau, for example, was more than seven years old when Auschwitz was established, and clearly influenced it Also, despite its unprecedented size, most registered KL prisoners – that is, those forced into SS barracks and slave labor – were detained elsewhere; even at its biggest, Auschwitz held no more than around one-third of all regular KL inmates. The greater majority of them died elsewhere, too, with an estimated three-quarters of registered KL inmates perishing in camps other than Auschwitz. It is important, then, to demystify Auschwitz in the popular conception of the camps, while still emphasizing its uniquely destructive role.

Wachsmann spends an illuminating amount of time on Theodor Eicke, whom he describes as the “godfather” of the KL system:

He was a roughneck, a bully, and a fanatical Nazi. Always spoiling for a fight, this overbearing and vindictive man suspected foes everywhere. Feared by his rivals for his obstinacy and temper, he felt that his destiny would finally be fulfilled under Nazi rule, after years of personal struggled and frustration.

In many ways, it was Eicke who provided the muscular drive for the framework SS leader Heinrich Himmler expanded throughout the Nazi world, creating a system that would ensnare 2.3 million men, women, and children and kill, according to Wachsmann, roughly 1.7 million of them in the course of the war. Even as early as 1934, the old camp installation at Dachau already existed, used to house political prisoners who were comparatively well treated until Hitler's radicalization of his regime during the three-day “Night of the Long Knives” in the summer of 1934, in which hundreds of Hitler's enemies and skeptics were murdered – and in which the SS went on a rampage within the confines of Dachau itself:

The murders continued deep into the night, after cars brought more “traitors” from Munich to the camp. Like von Kahr, most of them died in or around the bunker, but at least two men were executed in the harsh glare of camp searchlights on the SS shooting range. The Dachau inmates, locked into the camp compound, heard the shots, followed by roars of SS men intoxicated by bloodshed and alcohol; on the orders of Eicke, who was in triumphant mood, beer flowed freely in the SS canteen, with loud music playing. The macabre SS party was periodically interrupted by more shootings and beatings: some victims were tortured to death, their faces smashed and their bodies butchered.

Mountains of KL records were destroyed by the SS and the Nazi government, and a great many of the installations themselves were destroyed in the war's final months or immediate aftermath – and yet what remains is still a staggering amount to shift through, and Wachsmann's skill at pacing his narrative ensures that the reading experience might be fatiguing but is never overwhelming. He seeds his narrative with the plentiful pockets of human drama that make this subject so compelling – a tactic many researchers and writers in this field neglect. The moments he dramatizes are hard to read, naturally:

In addition to death by deprivation, the Camp SS relied on mass executions to decimate the weak. Lethal selections expanded across the remaining KL in the early months of 1945, probably in line with WVHA orders. The SS killed several tens of thousands of frail prisoners by shooting, lethal injection, or gas, to rid the camps of prisoners seen as health risks, drains on resources, and obstacles during evacuations. Sometimes the SS had chosen its victims upon arrival. Further selections followed in the compounds, especially inside the death zones. In Uckermark – a former police camp for “deviant” girls and young women, which was largely taken over by the Ravensbruck SS in January 1945 and turned into a dumping ground for the weakest and oldest women from the main camp and its satellites – the SS conducted daily selections. “We may be sick, but we are still human beings!” one wrote in despair on February 9, 1945. Those who were spared listened as the victims were driven off on SS trucks, cries and screams growing fainter.

Those cries and screams have by now of course faded completely and been replaced by histories. KL is one of the best of those histories for the new century, a comprehensive and ground-clearing work of research and a wrenching work of narrative. It's gruesome reading, but you're in masterful hands the entire time.