Battles & Wars › World War II
The Holocaust
1941–1945 (persecution from 1933)· Event· Europe
Well documentedSolid records, physical evidence or scientific consensus.
Nazi Germany's systematic murder of about six million European Jews, alongside the persecution and killing of Roma, disabled people and others.
See it on the Battles & Wars map →What happened
After Hitler took power in 1933, German Jews were stripped of rights, property and citizenship. During the war, Germany and its collaborators confined Jews in ghettos. From June 1941, SS mobile killing units, police and local collaborators shot an estimated 1.5–2 million Jews in occupied Soviet lands. In January 1942 the Wannsee Conference coordinated the 'Final Solution': deportation to death camps such as Treblinka, Sobibor, Belzec and Auschwitz. Roma, disabled people, Soviet prisoners and Poles were also murdered in huge numbers.
Why it matters
Its scale and bureaucratic method reshaped law and memory: the word 'genocide' (coined 1944), the UN Genocide Convention, modern human-rights law, and international support for a Jewish state.
How we know
Germany's own records, including killing-unit reports, Nuremberg trial evidence, deportation lists, the camp sites, Allied intelligence, and tens of thousands of recorded survivor, perpetrator and liberator testimonies.
Still debated
Historians debate exactly when the decision for total extermination was made in 1941, and how far it came from Hitler's orders versus escalation from below.
Inside this (1)
Connections (7)
▸Armenian genocide preceded and is often compared with The HolocaustMostly agreed
The connection
The Ottoman destruction of the Armenians in 1915–17 was a modern state's attempt to eliminate a whole people under cover of world war, and it went largely unpunished. Raphael Lemkin, who coined the word 'genocide' in 1944, was moved by both cases. Scholars compare them for their use of wartime secrecy, deportation and bureaucracy.
When and how
Ottoman Anatolia, 1915–17, and German-occupied Europe, 1941–45; German officers serving with their Ottoman allies witnessed the earlier killings.
How sure are we?
Lemkin's own writings cite the Armenian case as a reason he sought a law against genocide; German diplomatic reports from 1915 show awareness in Berlin.
Debates and open questions
Hitler's reported 1939 remark 'Who, after all, speaks today of the annihilation of the Armenians?' has disputed sourcing; Turkey's government still rejects the genocide label.
▸Adolf Hitler was the driving force behind The HolocaustWell documented
The connection
Hitler's obsessive antisemitism, set out in Mein Kampf, shaped Nazi policy from 1933. In January 1939 he publicly 'prophesied' that a new world war would bring 'the annihilation of the Jewish race in Europe'. Under his authority the regime moved from persecution to mass murder, organized by Himmler's SS and carried out by many thousands of others.
When and how
Germany and occupied Europe, 1933–45; Heinrich Himmler, Reinhard Heydrich and Adolf Eichmann organized the killing on the leadership's authority.
How we know
His speeches, Himmler's notes of their meetings, Goebbels's diaries and perpetrators' testimony; no single signed extermination order has ever been found.
Debates and open questions
Whether Hitler gave one decisive order, and when, is still debated; historians propose dates ranging from summer to December 1941.
▸Operation Barbarossa opened the mass-murder phase of The HolocaustWell documented
The connection
Barbarossa was planned as a war of annihilation. Behind the advancing army, SS Einsatzgruppen (mobile killing units), police battalions and local collaborators shot Jewish men, then women and children. At Babi Yar near Kyiv, nearly 34,000 Jews were murdered in two days in September 1941. This escalation led on to the death camps.
When and how
Occupied Soviet territories, including the Baltic states, Belarus and Ukraine, from June 1941; about 1.5–2 million Jews were shot by 1943.
How we know
The killing units' own reports, tallying victims, were evidence at the 1947–48 Einsatzgruppen Trial at Nuremberg; researchers are still locating mass graves.
Debates and open questions
Historians debate whether the shift to killing women and children in mid-1941 came from a central order or from escalation by local commanders.
▸Auschwitz-Birkenau was the largest killing center of The HolocaustWell documented
The connection
Auschwitz combined a concentration camp, a slave-labor complex and, at Birkenau, an extermination center. About 1 million Jews were murdered there, roughly one in six Holocaust victims, deported from Hungary, Poland, France, the Netherlands, Greece and elsewhere. In mid-1944 alone over 400,000 Hungarian Jews were sent there, most killed on arrival.
When and how
Oświęcim, in German-annexed southern Poland; mass gassings at Birkenau ran from 1942 until late 1944.
How we know
Camp records, deportation lists, the 'Auschwitz Album' photographs, perpetrators' testimony and historian Franciszek Piper's research on the death toll.
Debates and open questions
Because most victims were killed on arrival without registration, totals are estimates; about 1.1 million is the accepted scholarly figure, replacing a mistaken Soviet claim of 4 million.
▸The Holocaust was perpetrated during World War IIWell documented
The connection
War made the Holocaust possible: conquest brought millions of Jews under German control, wartime secrecy gave cover, and the 'war of annihilation' in the east removed remaining restraints. Most victims lived in Poland and the Soviet Union, where German occupation was harshest.
When and how
German-occupied Europe, 1939–45, above all Poland, the Baltic states, Belarus and Ukraine.
How we know
Nazi documents tie the timing of mass murder to the course of the war; the Allies' December 1942 joint declaration shows they knew of it.
Debates and open questions
Whether the Allies could have done more, for example by bombing the rail lines to Auschwitz in 1944, is debated.
▸The Holocaust boosted support for the Jewish state that fought 1948 Arab–Israeli WarMostly agreed
The connection
The murder of about six million Jews convinced many Jews and much of the world that Jews needed a state of their own. Hundreds of thousands of survivors were stranded in displaced-persons camps; many reached Palestine, some fighting in 1948. Sympathy helped win the 1947 UN partition vote and quick US and Soviet recognition of Israel.
When and how
Europe and Palestine, 1945–1948: displaced-persons camps in Germany and Austria, the UN partition vote on November 29, 1947, and Israel's declaration on May 14, 1948.
How sure are we?
Diplomatic records, the 1947 UN committee's visits to displaced-persons camps, and immigration figures document the link; Zionism itself predated the Holocaust by decades.
Debates and open questions
How decisive the Holocaust was, versus decades of Zionist state-building and Britain's withdrawal, is debated; Palestinians stress they paid for crimes committed in Europe.
▸IG Farben co-owned the firm that supplied Zyklon B for The HolocaustWell documented
The connection
Zyklon B was a cyanide pesticide sold for delousing. Its license belonged to Degesch, owned 42.5% by IG Farben, along with Degussa and Goldschmidt. From 1941 the SS used it in the gas chambers of Auschwitz-Birkenau and Majdanek; most of the roughly 1.1 million people murdered at Auschwitz were killed with it.
When and how
Degesch, Frankfurt; distributors Tesch & Stabenow of Hamburg and Heerdt-Lingler; Auschwitz, from the first gassings in September 1941 through 1944.
How we know
Shipping records and invoices, the 1946 British trial of Tesch & Stabenow's owners, and the IG Farben trial documents.
Debates and open questions
Who knew what is still argued. Degesch's manager, Gerhard Peters, was convicted in West Germany in 1949 but acquitted at a 1955 retrial; IG's board was never shown to know.