Neo-Nazis and other Antisemites claim that academics are forbidden from discussing the holocaust or questioning the Jewish narrative. This, we all know, is so incorrect that it's not even wrong but it does lead to this question: how has the historiography of the Holocaust changed over the years?

/u/hillsonghoods has already linked some of my previous answers (thank you!) but one thing I haven't really addressed so far in them is that in a lot of ways for the first fifteen or so years after the war, there wasn't so much a historiography of "the" Holocaust.

What I mean by that is that when it comes to researching and trying to understand the crimes the Nazis committed, the early focus was not on what we understand today as the Holocaust, meaning the systematic, bureaucratic, state-sponsored persecution and murder of six million Jews and up to half a million Roma, Sinti, and other groups persecuted as "gypsies" by the Nazi regime and its collaborators but on political and national victims. What I mean by that is that early historiography tended to resemble very much a narrative of the Holocaust as it was in the socialist bloc of Europe (and as it remained even as Western historiography shifted).

Political victims of the Nazis, be they communists, socialist or otherwise politically opposed, were front and center in this early historiography of Nazis crimes. One of the first major works about Concentration Camps that surpassed autobiography into something that can be considered adhering to historiographical standards was Eugen Kogon's Der SS-Staat. Das System der deutschen Konzentrationslager (The SS-State. The System of German Concentration Camps), published in 1946. Kogon, though born to a Jewish mother, had spent his childhood in Catholic institutions and after the Nazi take over of power had been engaged in the political resistance due to his deep catholic convictions. He was arrested three times and the third time, in 1939, deported and arrested in Buchenwald where he would spend the rest of the war. A sociologist by trade, he wrote Der SS-Staat after his liberation in 1945 and intended it to be a sociological and political treatise about the Concentration Camps, which was in part, very much colored by his own experience. His work is still read and has been printed since in the 44th edition but what is very noticeable about it is that Kogon mentions extremely little about either Jewish prisoners nor about the genocide of the Nazis. His work focuses on the Concentration Camps as he as a political prisoners experienced them (including a noticeable disdain for both fellow prisoners imprisoned as homosexuals and criminals).

This was very much the trend in the early years after the war and only little by little works that focused on the genocidal aspect of the Nazi state did emerge. In 1953 the British historian Gerhard Reitlinger published two book focus on what would later become known as the Holocaust: The SS: Alibi of a Nation and The Final Solution. Especially the latter taking the title from the term the Nazis had used for their undertaking to murder the Jews of Europe was a highly important book for the historiography. Reitlinger was indeed the first to work with a variety of documents that had emerged during the Nuremberg trials and that historians of the Holocaust today are highly familiar with like the Einsatzgruppen Reports or the so-called Korherr Report (a 1943 report about how the murder of Jews was proceeding). He was also the first historian who was able to conclude that the Soviet claims of 4 million dead in Auschwitz were not correct (the Soviets had initially assumed that the crematoria at Auschwitz had operated at full capacity 24/7 for several years – a claim that when it was corrected by historians they still stuck by for political expediency).

But even with Reitlinger's work, the real, big start of what can be called Holocaust historiography was 1961's The Destruction of the European Jews by Raul Hilberg. Hilberg was a graduate student in the 1950s and under the impression of his own work for the official US war documentation project and the Ulm Einsatzgruppen Trial in Germany (the first big scale war crime trial in Germany since the Nuremberg trials) he decided to write his PhD dissertation on the murder of the European Jews at the hands of the Nazis. Sifting through thousands upon thousands of documents collected as evidence for the Nuremberg Trials, Hilberg produced a 1,273-page magnus opum in three volumes detailing the Nazis Jewish policy from 1933 to 1945 in Germany and every occupied and controlled territory. To this day Hilberg's work (with various updates) is a standard work as whenever you want to look something up about a specific country and the Holocaust, you can always first look in Hilberg.

Only thing was – and this is a pretty good indication for the state of historiography in 1961 – at the time, nobody wanted to publish it. Princeton Publishing turned down the book and Hilberg had to turn to a small Chicago Publishing House to get it out, though with some delay because no editor could be found at first. Similarly, while German publishing rights were acquired in the 60s, only a very small edition was printed and it would take until the 1980s until a good and serious German edition would be published in the Fischer Publishing House.

The thing that would change the historiographical landscape however was the Eichmann Trial in Jerusalem. Garnering world-wide attention, Eichmann and his role in killing Europe's Jews set off a wave of interest in the subject matter and a wave of publications though many of these weren't so much focused on what Hilberg had researched but under the impression of the emerging field of social history were located in the intentionalist-functionalist debate about the origin of the Holocaust.

"The Holocaust" as a name however only caught on (though it had been used earlier) with 1979's TV mini series "Holocaust", featuring among others, Meryl Streep and James Woods. After that, a wave of publications dealing with the Jewish victim's perspective started to be published and research, very prominently among the , the works of Saul Friedländer.

Since then, easily the biggest two developments were the Christopher Browning inspired emergence of the field of perpetrator studies, meaning the research focus on what made the perpetrators of the Holocaust act as they did and – even more importantly – the opening of the Soviet archives and the archives of other formerly socialist states in the early 90s.

The opening of the Soviet archives has enabled historians not just produce new and interesting works (virtually the start of the focus on the Wehrmacht's role in the Holocaust started around the same time) but it has lead to the discovery of things we didn't know about beforehand at all. When Hilberg wrote his book in the 60s he once said that about 80% of what happened in the USSR is unknown to historians. While that was a slight overestimation in my opinion, he was right in as far as for example, the discovery of Maly Trostinec went. Before the Soviet archives opened the Maly Trostinec extermination camp had been unknown in Western Holocaust historiography. It was a genuinely new discovery.

Similarly, the Soviet archives also lead to a bigger focus on how the treatment of various other victim groups and the Holocaust related. As f.ex. Susanne Heim and Götz Aly showed in their book Vordenker der Vernichtung, the Generalplan Ost and the deportation of Polish citizens to make room for German settlers and the the start of the killing of the Jews was imminently related.

So, this is basically a quick overview of the development of the historiography. I've been forced to leave a lot out but one last thing I'd like to address is the numbers. The number of deaths has over the years – and with discoveries such as Trostinec – rather increased than decreased. Reitlinger and Hilberg estimated the number of Jewish deaths closer to 5 million than to 6 due to the fact that the material from the USSR was still not available to them. Overall however, the number has remained pretty much in that range from the very beginning, simply because it was what the Nazis' documents themselves indicated and what matched with population statistics in Europe to boot.