In early 1947, the Chief Counsel of the United States Nuremberg Military Tribunals, Brigadier General Telford Taylor prepared indictments against the second tier Nazis. By then the liberation of the concentrations camps, and the research, testimony and publicity surrounding the international trial against the Nazi leadership, had revealed the horror and extent of the regime’s war crimes and crimes against humanity. An advisor to the U.S. prosecution team, Raphael Lemkin lobbied for the inclusion of a new crime, which he coined “genocide.” With this growing awareness of the Holocaust, Telford Taylor sounded out his legal team about the possibility of holding a trial that focused exclusively on the Nazi extermination of six million European Jews, stressing “that this is by far the most important and sinister item in the entire Nazi history.” Though such a trial did not occur, it is striking that Taylor and others, who first sifted through tons of captured German records, conducted interrogations of perpetrators, and recorded witness testimony from victims and bystanders, realized that the “Final Solution” held an outstanding place in the history of Nazi crimes.The U.N. Convention on the Prevention and Punishment of the Crime of Genocide was passed in 1948, yet it would take decades for the popular and academic recognition of the Holocaust as a major event to be memorialized, studied, and taught. There were exceptions—for example, Jewish survivor initiatives to collect testimony for memorial (Yizkor) books. In the 1950s, survivor-historian from Lviv and first director of Poland’s Central Jewish Historical Commission Phillip Friedman published an extensive to-do list of Holocaust research. He identified six main themes and dozens of subthemes: 1) The Nazi Philosophy and Strategy of Annihilating the Jews; 2) Legislative and Economic Action Affecting Jews in 1939–45; 3) Acts of Terrorism and Extermination; 4) Impact of Nazi Persecution on Jewish Life; 5) The Outside World: External Factors; and 6) Relations Between Jews and Non-Jews in the Nazi-Occupied Countries. This was his remarkably comprehensive outline for a grand narrative of the Jewish catastrophe. However, nearly all of the items on his agenda remained untouched until the 1980s. There was no field of Holocaust studies—Gerald Reitlinger, Eugen Kogon, Raul Hilberg, Franz Neumann, Hannah Arendt (early authors of books on the SS and Nazi state) would not have self-identified as scholars of the Holocaust. Rather, research focused on Nazi Germany as a totalitarian or fascist dictatorship, and the Holocaust was one policy, usually referred to in Nazi terms as the Final Solution. Now, we see this turned on its head. Holocaust studies dominate interpretations of Nazi Germany, and in many ways of modern Germany itself. And the history of genocide has started to shape how we define systems of rule, unbridled abuse of power, and political economies of nation states, dictatorships, and empires.Holocaust research and teaching blossomed in several places where seeds were sown by intellectuals who had been in exile during the Nazi era and survivor scholars who had emigrated after the war to North America, Britain, Israel, and Australia. These mostly non-historians in political philosophy, sociology, psychology, literature, and theology grappled with the collapse of civilization as a problem of human existence, of suffering, good, evil, sociopolitical structures, personality disorders, and the Death-of-God. Then in the 1980s, a new generation of historians of Nazi Germany concentrated on this “most important and sinister item,” as Telford Taylor had put it, and specifically on the decision-making and Nazi implementation of the Final Solution, spawning the intentionalist-structuralist debates. In the post-Soviet era they were joined by a new generation of German and European scholars who completed their doctoral dissertations on regional studies about the implementation of the Final Solution in Eastern Europe and on Nazi anti-Semitic practices in Germany and the Reich’s annexed territories. In this chronology of interpretations and approaches, surprisingly victim studies and Jewish Studies appeared later at the turn of the 21st century.Now the field has exploded. Reconstructing the events of the Holocaust has mobilized cadres of professionals besides historians, lawyers, criminologists, forensic scientists, archaeologists, curators, conservators, anthropologists, genealogists, musicologists, among others. The magnitude of the event is staggering, and so are the mountains of evidence. One cannot read every record and listen to every testimony. The number of hours of video testimony at USC Shoah Foundation’s Visual History Archive exceeds 165,000 hours of footage, or about 20 years of viewing, and those are the voices of some 55,000 survivors, a fraction of the 6 million who were killed. We have yet to identify about half of the Jewish victims murdered in Russia, Lithuania, Belorussia and Ukraine. They remain the missing-missing.Today more scholars are engaged in the topic than ever before. Yet, contrary to popular belief, we do not know all there is to know about the Holocaust. We have laid the foundation with a basic narrative of events, with key actors from Hitler to the ordinary men and women, with varied theoretical explanations of modernity, and with myriad motives and historical forces such as anti-Semitism, peer pressure, sadism, anti-communism, nationalism, sexism, and imperialism, to name a few. A lot has been achieved since the 1950s and early ’60s when those early studies appeared on the SS, drawing from the Nuremberg trials and the captured German records. But our research remains unfinished. In fact most of the non-German documentation across Europe and around the globe has only become accessible in the past 25 years or so, and major collections are just being opened now or remained. In December 2015, the French Ministry of Defense opened up its postwar trial records, and the Dutch National Archives is declassifying theirs now and allowing the United States Holocaust Memorial Museum to survey and digitize them (they will be available in 2025). We will be awash in millions of pages, in thousands of cases against German perpetrators and French and Dutch collaborators in France, the Netherlands, and northern Africa, for example. Meanwhile, the Vatican just turned down the Museum’s attempt (and not its first try) to access the finding aids and records on Pius XII and the wartime held in the Vatican Secret Archives. Only the Holy Father can open this collection and grant access to it. There is much more to discover, and in many places the reluctance to face this history persists.Of late, the history of the Holocaust has been losing its center in Germany and has become a subject of European history, and especially of Eastern European history, or what Timothy Snyder described as the Bloodlands. The Europeanization of the Holocaust, above all its “spatial turn,” challenges researchers to become transnational comparativists, which entails paradigm shifts, acquiring additional languages and interdisciplinary methodological approaches. It also forces a rethinking of the distribution of power in the Nazi system, the imperial dynamic of the center and periphery, as well as the relations between the occupier and occupied. The categories of victims and perpetrators have expanded to include non-Jews and non-Germans. In the time remaining I would like to focus on four recent research trends that have stimulated this European turn: (1) German killers and European crimes scenes, (2) transnational biography, (3) collaboration, and (4) big data and digital archives.The European TurnIntroducing a European paradigm is not ahistorical. By intent, design, and implementation, the Holocaust was a European event. Yet the European dimensions of the Holocaust appear in multiple forms, which are still being identified, researched and compared. For example, the targeted victim groups spanned European borders, since enemy “racial” and political categories of Jews, communists, Roma, the disabled and “Slavs” superseded nationality. The Wannsee Protocol, a document that summarized an infamous January 1942 discussion on the “solution to the European Jewish Question” contains lists of Jews from all European countries, including those that were not occupied by the Germans (such as England, Ireland, and Switzerland). Another European facet was the railway system of deportations and interconnected camps—the victims’ transnational paths of persecution, illustrated in maps that show these routes and recounted in the memoirs of survivors who described being transported, for instance, from France to Poland, from Germany to Latvia, and from Hungary to Ukraine. At Auschwitz-Birkenau, we can see the European dimensions of the inmate experience. Primo Levi described the bewildering cacophony of European languages as a Tower of Babel. Prisoners from across Europe who found themselves interned in the camp system in Nazi-occupied Poland (and in Germany) entered a microcosm of European cultures and were forced to live and—for most Jews who arrived there—die in what they often depicted as Dante’s “Inferno.” Thus histories of Auschwitz-Birkenau are by definition European history.Yet European histories of the Holocaust that deal with the enmeshed cultures of victimization are rare, and the few that have appeared always seem to fall short because of the enormity of source material in multiple languages, as well as the intellectual challenge of comprehension and comparison. They, like perpetrator and bystander histories, focus on the actions of one national or ethnic group and not their interactions. Indeed, as a central theme, the European or the transnational appears mostly in postwar subjects such as comparisons of justice, memorialization, and restitution of Jewish property.The recent historiographical turn to the theme of Europe was inspired by political developments in Europe. In retrospect, it is hard to imagine this turn without the watershed events of the 1990s—the opening up of the Soviet archives, and the bridging of Eastern and Western Europe around the European Union’s historical agenda of promoting Holocaust education and memorialization as a basis for cooperation. Countries seeking membership in the European Union and its attendant economic benefits were required to form historical commissions to come to terms with their national histories of collaboration. Scholars on the commissions and historians who served as expert witnesses mined archives in Poland, Romania, Lithuania, Slovakia, and Hungary and discovered that the crimes of the Holocaust could no longer be blamed entirely on Nazi Germany. In effect, these commissions began the work of decentring Berlin and Europeanizing Holocaust historiography. Collaboration became at once a touchstone of polarizing national identity politics as well as of a shared European past in WWII and the Holocaust.Jan-Werner Müller studied these trends in more depth in his essay, “Europe,” which was published in the Oxford Handbook of Holocaust Studies. As he convincingly argued, “Nazi rule as a defense against Bolshevism, had been completely reversed 60 years after the Holocaust: It now is supposed to stand for tolerance, nondiscrimination, and appreciation of diversity.” The inversion of the concept from its dark Nazi past to a bright European future took on a redemptive political, moral, and historical imperative. Holocaust education and memorialization as a common European project gathered momentum in the 1990s and spurred fruitful research by scholars, but these progressive movements also tested these very values and revealed in the 21st century the persistence of national extremism, xenophobia, and anti-Semitism. We are witnessing backlashes in Hungary, Poland, and Slovakia.In Holocaust studies, the European turn pivots away from the fragmentation of micro-studies and nationalist paradigms toward the search for unifying themes such as anti-Semitism. It is propelled by the vast archival sources as well as theories of genocide that encourage scholars to explore broader sociological explanations of, in Christian Gerlach’s terms, extremely violent societies. On the more technical level, the centralization of archives and digitization of records at the U.S. Holocaust Memorial Museum, and recently in the EU-funded European Holocaust Research Infrastructure, have played a role. Centralizing European archives as a digital gateway has created a virtual experience of research without borders. In effect, the growing network of archives and their users, which is facilitated through new technological means and platforms, has encouraged a Europeanization of the Holocaust.I. German Killers and European Crimes ScenesThe decentring of Berlin began with research in the state and regional archives in the former Soviet Union. Scholars began to appreciate the importance of the places of ghettoization and mass murder as sites of inquiry and testimony collection. And they realized that during the war, Nazi leaders did not govern exclusively from Berlin. On the contrary, in September 1942, Reich Führer of the SS Police—Heinrich Himmler—assembled his top brass at his field headquarters in Ukraine. At one point in his long lecture, he urged his SS and police commanders to “make decisions in the field.” In the 1990s, the origins debate branched out into studies of regional decision-making, locating the center in the periphery and tracing the dynamics of policy formulation and implementation vertically from the bottom up and top down, and horizontally across German agencies, including those that dealt with non-German Axis leaders in Slovakia, Hungary, Croatia, and Romania. As a result, the evolution and implementation of the Nazi Final Solution as a state policy has been recast as a series of radicalizing, incremental decisions that occurred chronologically and in different key regional centers (e.g., Pretzsch, Lublin, Minsk, Mogilev, Warsaw, and Zhytomyr). Is the lack of one Hitler order as important as the existence of hundreds, perhaps thousands of orders issued by regional commanders in the SS police and the Wehrmacht, and by their indigenous helpers in their native languages?Both in studies of German empire-builders who circulated throughout Europe and of the millions who experienced Nazi rule, the theme of proximity is significant. How closely did the violence enter into the everyday lives of Europeans? The nearness of the crimes scenes to the scholars researching it is also a vexing matter. The Holocaust is recent history and contemporary history. It is being written from private archives, from interviews with survivors, direct witnesses, and in former camps and places where bones, ashes, and personal effects are uncovered. Historian Karel Berkhoff studied the Soviet obliteration and dispersal of ashes at Babi Yar as the history of the communist party’s suppression of the history there and the continuity of anti-Semitism. With digital mapping software, historians can more easily plot and visualize the paths of deportees or the layout of a ghetto, thereby corroborating and combining testimonies.A proponent of the Geographical Information System, historian Waitman Beorn applies spatial concepts to his analysis of Wehrmacht complicity. After retracing the steps of Jewish marchers who were led to the mass shooting site in the Skrydlevo forest in Belarus, he argued that “this journey impressed upon me the value of actually visiting these sites of killing and of thinking of the killing as a spatial problem, for this is how the perpetrators themselves viewed their task in the East and … the task of murdering Jews in general.”Beorn reexamines key documents of the Holocaust with a new emphasis on the meaning of topography and distance. After the Mogilev Conference of September 1941, where the killing of Jews was sanctioned by generals in the Wehrmacht and Waffen SS as an acceptable form of “anti-partisan” warfare, local army commanders (such as those attached to the 707th Infantry Division in Belarus) were empowered to execute or ghettoize Jews in the countryside. The killing sites that they selected (often with the help of local collaborators) varied significantly (ravines, Jewish cemeteries, wells, peat bogs, shell craters), but they were not random. They were selected for physical, spatial, and ideological reasons (e.g., ease of excavation, concealment, and access). Beorn questioned whether these spatial decisions reveal the attitudes of ordinary soldiers on the ground who became complicit, and he discovered that “one attribute all soldiers had concerning their participation in a variety of killings across the Soviet Union was that of position.” Soldiers were routinely tasked with encirclement operations. They formed a cordon around a village to prevent Jews from escaping deportations or shooting sites. Soldiers could decide on the spot if they might remain at the edge of the operation, block Jews who beseeched them to open up the circle to allow escape, or if they might move closer to the action in the center. These choices of position reflected attitudes and shaped peer relationships and individual reputations. Those who opted to stand outside the cordon were deemed weaker characters. Postwar memoirs and testimonies of soldiers continued to draw on spatial references. When questioned about massacres, a former soldier gave a vivid account, which proved his proximity but then claimed that he was hundreds of meters from the violence. This amounts to a proximity version of self-exculpatory testimony and a form of psychological distancing. Beorn concludes that “the overlaying of a mental (moral) map on the physical position of individuals may be a useful approach.”Proximity determined the emotional impact—how closely one directly experienced the violence. A Jewish-Lithuanian philosopher of this era, Emmanuel Levinas, described the act of violence as an ontological event that changes the lives of all involved: victims, survivors, perpetrators, collaborators, witnesses, and their descendants. Historians interact with those involved and their descendants. They study personal photographs, diaries, letters, and recollections. These opportunities to get closer to the past in a more intimate, personal way also challenges historians to maintain their distance and to avoid bias and moralizing.II. BiographyFor scholars of Nazi Germany and the Holocaust in Europe, one way to avoid the fragmentation of micro-histories or of disconnected mass murder sites is through biography and studies of socio-political networks. High ranking and ordinary German occupiers—be they policemen, regional governors, plunderers, technocrats, or women in various supportive roles—moved around Europe. The individual and collective biographical trend stress the interwar period as formative years or as a stage of development that is then put to the test of wartime of adaptation, complicity or resistance, and all the gray areas of behavior in between. Catherine Epstein’s work on Wartheland Gauleiter Arthur Greiser, Martin Cueppers’ on gas-van expert Walther Rauff, and various collections of biographies such as Die Taeter der Shoah paint a more nuanced picture of individual agency and character development. In Mary Fulbrook’s A Small Town Near Auschwitz: Ordinary Nazis and the Holocaust (2012), her main subject is Udo Klausa, a county administrator sent to Bedzin to govern the area around Auschwitz. Klausner is close to an epicenter of the mass murder and forced to confront the depths of his anti-Semitism, at first indifferent to the Jews and then in the face of the genocide struggling with his conscience and humanity. Rather than condemn or judge Klausner as a “perpetrator” Fulbrook reconstructs the complex pressures and changing circumstances that he navigated.The biography boom has also placed the Nazi era in a 20th-century narrative of German history. The question of continuity in German history is no longer about tracing the peculiar development of Germany’s special path to Nazism, but rather about charting the Reich’s radical turning points during the war and tracing how this catastrophe reverberated into the postwar era. Holocaust history has been pushing the chronology of Nazi Germany forward into aftermath studies. As historians David Blackbourn and Helmut Walser Smith observed, “Once the big question was, how did we get to 1933, now the question is ‘how was the Holocaust possible?’ 1941, not 1933 has become the ‘vanishing point.’” The continuity questions hinge on the wartime and zero hour of 1945. The deep causes, structural ones that extend backwards into the 19th century (and earlier) are treated lightly, if at all. While the chronology contracts around the Holocaust, the space of action expands beyond Germany’s shifting borders. Most ordinary Germans in the 20th century left their hometowns, willingly or not, or if they did not, the spaces in which they lived changed dramatically from regime to regime, occupation, to reunification, as the German question and the criminal legacy of the Third Reich became central to European history.III. CollaborationBefore the rise in Holocaust studies in the 1990s, collaboration was defined mainly by its occurrence in France and Norway, in its crudest depictions as sexual “horizontal” female collaboration and as political accusations of betrayal with the label of a quisling (Vidkun Quisling was head of the Norwegian collaborationist government). And in the case of France this history may be rewritten based on the recently declassified French Ministry of Defense records (among the 900 dossiers that I surveyed, several dozen list female defendants indicted for “relations avec les allemands”). Holocaust researchers discovered that the voluminous trial records in archives in former communist countries identified “traitors to the homeland” as those who committed war crimes against “peaceful Soviet citizens.” In fact across Europe most individuals indicted for crimes related to the Holocaust were not Germans but Poles, Lithuanians, Ukrainians, Latvians, and Byelorussians. The current political and sociological implications of this wartime anti-Semitism proved incendiary. Jan Gross’s Neighbors (2001), in which he describes how roughly half the population of Poles in the town of Jedwabne slaughtered and burned alive the other half of the town’s population of Jews, set off a firestorm in Poland epitomizing how individual nations have been coming to terms with complicity in the Holocaust, expanding Hitler’s shadow beyond Germany and the Germans and illuminating the depths of violent anti-Semitism across Eastern Europe. Complicity was more than a local affair, as in Jedwabne, or Vilnius, or Kiev. In Timothy Snyder’s comparative study, Bloodlands: Europe Between Hitler and Stalin (2010), he argues in a manner reminiscent of the totalitarian theorists decades earlier that Hitler and Stalin had more in common with one another, particularly in their shared desire to destroy Poland and exploit Eastern Europe as empire builders and ideological foes. Yet there were other important regional leaders whose biographies intersected and shaped European history, not just Hitler and Stalin, such as the entanglement among the Axis leaders Mussolini, Tiso, Antonescu, Laval, Horthy, Franco, and Kvaternik.The radicalization, escalation narrative is no longer restricted to studies of German rank and file but narrated as Polish, Ukrainian, Lithuanian, French, Hungarian, Romanian, and Dutch history. Jan Grabowski’s regional case study of the Polish Blue Police (2013) is exemplary in this regard. Polish police wishing to avoid harsh reprisals from Nazi leaders secretly killed Jews they uncovered in hiding. Local Poles assisted by turning over Jews fearing that the discovery of Jews would lead to more violence against them and their families residing in or near the hidden Jews. Rather than judge and condemn collaborators, historians are teasing out the myriad motives and local pressures and perceived crises. But more could be done to show how the biographies of local non-Jewish actors in the occupied population intersected with German overseers, producing a negative synergy that expanded the number of Jews murdered across Nazi occupied Europe.IV. SourcesObviously the Europeanization of Holocaust could not have occurred without the collapse of the Soviet Union. As long as the Iron Curtain divided scholarship between East and West and blocked access to archives, there existed scarcely an opening for the many topics referenced here: spatiality, imperialism and colonialism, Eastern Europe’s killing fields, and the transnational biographies and forms of collaboration. Research has increased because of major declassification efforts and rise in oral history and memoir writing, and many collections (digital and in print) provide powerful material which number in the tens of millions of pages and tens of thousands of videotaped testimony). The International Tracing Service archives and restitution records are already moving the field into new directions that will represent the experiences of millions of non-Jewish forced laborers and displaced persons. While some historians bemoan the continued ethnic approach to the past (i.e., reifying national differences and assuming stable, definable ethno-national identities), this approach is unavoidable in Holocaust studies since the Nazi era was a crisis of ethno-nationalism, statelessness, and near-triumph of the evils of racism. Whether or not one believed oneself to be German, Jewish, Polish, French, Slavic, or Nordic, these labels determined one’s destiny in Nazi dominated Europe. And they influenced the source material and how historians interpret it. For example, a large proportion of German Jews survived through emigration, and there exists more survivor testimony from western European Jews who survived Auschwitz-Birkenau than Jews who were deported to gassing centers in Poland or who were shot in Ukraine. Thus German Jews are overrepresented in the testimony, and the narrative of prewar Jewish life focuses on Hitler’s Germany. We know less about Jewish prewar life in other countries.The way we conduct our research has changed so dramatically in the past decades that it is hard now to discern the overall impact. We have become creatures of the database research and laptop search and find, not the paper-archival finding aid. The problem with the database is that it is mostly a fishing expedition, and inductive. Trolling databases and culling from them, like the International Tracing Service trove, is a form of discovery, and can illuminate broad patterns of experience and help one connect dots. Big Data can facilitate this as well, for example lists of personal effects in the ITS. At the ITS there are 30,000 of them, and a few months ago USHMM researchers led by Harvard historian Gabriel Pizzorno attempted a pilot study to identify any patterns, or configurations. They grouped a sample set of 300 by gender and age, since the objects had personal identifications attached to them. They belonged to political prisoners. The data analysis found that the elderly brought with them family silver, among other items, and the middle-aged prisoners brought their identification papers, jewelry in the form of watches (men) and wedding rings (women) as well as hard currency and personal photographs. Data reveals, but does not explain. What questions were posed to uncover such information and how can the findings be interpreted?Testimony as a source is increasingly turning to artifacts bolstered by museology and innovations such as the new David and Fela Shapell Family Collections, Conservation and Research Center of the USHMM, and the growing interest in material culture in Holocaust studies. We have been mining the audiovisual histories since Yale University founded its Fortunoff Video Archive in 1980. Photo albums and photos are studied and displayed as a form of testimony, images that visually document and if captioned can also narrate what happened. In a recent study by Leora Auslander and Tara Zahra, Objects of War: The Material Culture of Conflict and Displacement, scholars analyze objects refugees packed in their suitcases, or prisoners clung to in the camps, some necessary for survival, like an eating utensil or clothing, others more symbolic like a family photograph or wedding ring. Ausland and Zahra argue that “the meaning of things to individuals is often magnified or transformed entirely in the context of war and displacement” and personal objects for the victims under siege can help them “retain memories and maintain a sense of self.” Above and beyond the ancient history of looting, imperial consumption, cultural erasure and transfer, material culture studies provides another entry into understanding modern conquest and genocide but from the perspective of the victims of the violence. Their possessions, often the only trace we have of their lives, open a window into their experiences, emotions, values, and social relations. The provenance of an object—perhaps that family silver bears the stamp of a Viennese craftsman and was found in the barracks of Birkenau—can also help us trace wartime paths and fates.The overall growth in Holocaust studies is impressive but, like these singular material objects, fragmentary and often isolated. There are few central questions and binding themes found in earlier studies on anti-Semitism, the origins of the Final Solution, perpetrator motivations, and resistance of victims. If there were, then perhaps the responses of bystanders is the burning issue. The stress on multicausality has added the necessary nuance but diverted attention from core issues that engulfed all of Europe, the universal and specific cultural realities that drove human behavior that could be applied to genocide studies more broadly. At present there are few major debates driving the field. It is diffuse but more secure than ever.