The Holocaust was the systematic extermination of Europe's Jewish population in the Second World War, during which time, up to six million Jews were murdered as part of Nazi Germany's "Final Solution to the Jewish Question". In the context of the Second World War, the term "Holocaust" is traditionally used to reference the genocide of Europe's Jews, although this coincided with the Nazi regime's genocide and ethnic cleansing of an additional eleven million people deemed "undesirable" due to their ethnicity, beliefs, disability or sexuality (among others). During the Holocaust, Poland's Jewish population suffered the largest number of fatalities, with approximately three million deaths. Additionally, at least one million Jews were murdered in the Soviet Union, while Hungary, Latvia, Lithuania, the Netherlands and Yugoslavia also lost the majority of their respective pre-war Jewish populations. The Holocaust in Poland In the interwar period, Europe's Jewish population was concentrated in the east, with roughly one third living in Poland; this can be traced back to the Middle Ages, when thousands of Jews flocked to Eastern Europe to escape persecution. At the outbreak of the Second World War, it is estimated that there were 3.4 million Jews living in Poland, which was approximately ten percent of the total population. Following the German invasion of Poland, Nazi authorities then segregated Jews in ghettos across most large towns and cities, and expanded their network of concentration camps throughout the country. In the ghettos, civilians were deprived of food, and hundreds of thousands died due to disease and starvation; while prison labor was implemented under extreme conditions in concentration camps to fuel the German war effort. In Poland, six extermination camps were also operational between December 1941 and January 1945, which saw the mass extermination of approximately 2.7 million people over the next three years (including many non-Poles, imported from other regions of Europe). While concentration camps housed prisoners of all backgrounds, extermination camps were purpose-built for the elimination of the Jewish race, and over 90% of their victims were Jewish. The majority of the victims in these extermination camps were executed by poison gas, although disease, starvation and overworking were also common causes of death. In addition to the camps and ghettos, SS death squads (Einsatzgruppen) and local collaborators also committed widespread atrocities across Eastern Europe. While the majority of these atrocities took place in the Balkan, Baltic and Soviet regions, they were still prevalent in Poland (particularly during the liquidation of the ghettos), and the Einsatzgruppen alone are estimated to have killed up to 1.3 million Jews throughout the Holocaust. By early 1945, Soviet forces had largely expelled the German armies from Poland and liberated the concentration and extermination camps; by this time, Poland had lost roughly ninety percent of its pre-war Jewish population, and suffered approximately three million further civilian and military deaths. By 1991, Poland's Jewish population was estimated to be just 15 thousand people, while there were fewer than two thousand Jews recorded as living in Poland in 2018.

Throughout history, the displacement and migration of Jewish populations has been a repeating theme. In ancient times, the worlds Jewish population was concentrated in the Middle East, especially around Judaism's spiritual homeland in present-day Israel. However, the population distribution of the world's Jewry began to shift in the Middle Ages, with an increasing share living in Europe. Initially, Western Europe (particularly France, Italy, and Spain) had the largest Jewish populations, before they then migrated eastward in later centuries. Between the 18th and mid-20th centuries, over half of the worl'd Jews lived in Europe, with over 80 percent of these living in Eastern Europe.

Poland had become a refuge for Jews fleeing persecution in the Middle Ages, although shifting borders and foreign influence meant that long-term security was never fully attained, and a series of pogroms in the Russian Empire in the 1800s, and rising anti-Semitism in Central Europe in the early-1900s contributred to waves of migration to the United States and Israel during this time. After the Holocaust saw the genocide of up to six million Jews (over one third of the world's Jewish population), the share of Jews living in Europe dropped drastically, and emmigration outside of Europe increased. Today, the United States has the world's largest Jewish population in the world at around 7.3 million people, just ahead of Israel with 7.1 million.

Europe's Jewish population in 1939 was around 9.5 million people, and it is estimated that six million of these were ultimately killed by 1945. The persecution of German Jews escalated during the interwar period, particularly after Hitler's ascent to power in 1933, and again after Kristallnacht in 1938. However, the scale of this increased drastically following the German invasions of Poland in 1939 and the USSR in 1941, when Germany annexed regions with some of the largest Jewish populations in Europe. Extermination Camps As part of the "Final Solution to the Jewish Question", the Nazi occupiers established six extermination camps in present-day Poland; these were Auschwitz-Birkenau, Belzec, Chelmno, Majdanek***, Sobibor, and Treblinka. Prisoners, mostly Jews, were transported from all over Europe to these camps. Upon arrival, the majority of victims were sent directly to purpose-built chambers or vans, where they were murdered with carbon monoxide or Zyklon B gas. A relatively small number of prisoners were also forced to dispose of the victims' bodies, which often included their own family members, friends, or persons known to them. Most of the deceased were incinerated, and many of the camp records were destroyed; this means that precise figures for the number of deaths in extermination camps will never be known. It has been estimated that at least 2.7 million Jews were murdered in these six camps; over two thirds of these were killed at Auschwitz or Treblinka. Einsatzgruppen After extermination camps, the most common method of murder was through mass shootings. The majority of these shootings were not carried out by regular soldiers, but specialized task forces known as "Einsatzgruppen". Each group was just a few hundred men each, but they were responsible for some of the largest individual acts of genocide in the war. The largest of these took place at Babi Yar, near Kyiv in 1941, where almost 35,000 victims were beaten, humiliated, and then shot over a two day period. The Einsatzgruppen were most active in the annexed Soviet territories (although additional regiments were active in Poland and the Balkans), and their ranks were often bolstered by local volunteers. It has been estimated that Einsatzgruppen were responsible for the genocide of more than two million people in fewer than six years.

With the heightened threat to Germany's Jewish population following the Nazi Party's ascent to power in 1933, many German Jews chose to flee or emigrate. In 1933, Germany's Jewish population was approximately 500,000 people; by the end of the war, it is estimated that 300,000 fled the country, and 165,000 were murdered in the Holocaust. In order to flee, most Jewish emigrants from Germany had to give up the majority of their wealth to the German state, whose emigration tax and seizure of property stripped Jews of their financial assets. Destination and transit For Germany's Jewish refugees, the most common destination country was the United States, and almost half of all these refugees would arrive in the U.S. over this 12 year period. As the United States had a strict quota of 27,000 German migrants per year, many refugees were forced to enter via other countries. France was the second most common destination country, receiving 100,000 refugees. However, France was also used as a transit country for German Jews wishing to travel further afield, especially after it was annexed by Germany in 1940. This was also true for several other European countries, such as the Netherlands, which had provided protection for German Jews in the mid-1930s, before rapidly becoming very unsafe following the outbreak of war in 1939. The Frank family Possibly the most famous example of this was the story of Anne Frank and her family. Anne had been born in Frankfurt, Germany in 1929, but her family moved to the Netherlands in 1934 after Hitler came to power. The family then led a relatively comfortable and successful life in Amsterdam, with her father, Otto, founding his own businesses. When the Netherlands was invaded by the Germans in 1940, the family tried to emigrate once more; Otto had been granted a single Cuban visa in 1942, but the family was forced to go into hiding as the restrictions tightened. For the next two years, with the help of non-Jewish friends, they lived in secret in the upper floor of Otto's business premises with several other Jewish refugees, in a small space concealed behind a bookcase. In August 1944, through unknown means, the group was betrayed and then arrested by Dutch authorities, and the Frank family was sent to Auschwitz-Birkenau thereafter. Anne's mother, Edith, died of starvation in Auschwitz within five months of her capture, while Anne and her sister, Margot, died one month later after being transferred to the Bergen-Belsen camp in Germany. Otto was the sole survivor of the group. Otto's secretary, Miep Gies, had saved Anne's diary the day after the group was arrested, which she then gave to Otto; he then devoted much of the remainder of his life to the publication and promotion of his daughter's diary, which has now become one of the most famous and widely-read books in recent history. Additionally, the hiding space is now open to the public, and has become one of the Netherlands' most popular tourist museums.

On November 10, 1938, just two days after the Kristallnacht pogroms, the German government introduced the Judenvermögensabgabe; the Jewish capital levy. Jews with more than 5,000 Reichsmarks (RM) in assets were required to pay a 20 percent tax on all assets in order to meet a collective target of one billion RM. Despite inflated claims of Jewish wealth, the events of the preceding five years had financially crippled many of Germany's Jewish population, and it quickly became clear that the target sum would not be met, therefore the tax was increased to 25 percent in 1939. Jewish property This levy was introduced by Herman Göring, as a punishment for Jews and their so-called "hostile attitude" towards the German people. In reality, funds from the levy were to be used to repair the businesses damaged in the pogroms (the cost of which was estimated to be 225 million RM), which were then seized by the government and sold on to non-Jewish buyers. Many of these properties were confiscated through two additional decrees in 1938, which also saw authorities force Jewish businesses to sell selected assets at severely reduced prices. Deportation A clause of the Nuremberg Laws of 1936 stripped overseas German Jews of their citizenship and property; this rule was then applied to the thousands of German Jews who were deported to concentration and extermination camps in Eastern Europe after 1941. The remaining Jewish assets were seized by the Nazi regime and put towards the war effort, which ultimately included the systematic murder of many German Jews.

Most estimates place the total number of deaths during the Second World War at around 70-85 million people. Approximately 17 million of these deaths (20-25 percent of the total) were due to crimes against humanity carried out by the Nazi regime in Europe. In comparison to the millions of deaths that took place through conflict, famine, or disease, these 17 million stand out due to the reasoning behind them, along with the systematic nature and scale in which they were carried out. Nazi ideology claimed that the Aryan race (a non-existent ethnic group referring to northern Europeans) was superior to all other ethnicities; this became the justification for German expansion and the extermination of others. During the war, millions of people deemed to be of lesser races were captured and used as slave laborers, with a large share dying of exhaustion, starvation, or individual execution. Murder campaigns were also used for systematic extermination; the most famous of these were the extermination camps, such as at Auschwitz, where roughly 80 percent of the 1.1 million victims were murdered in gas chambers upon arrival at the camp. German death squads in Eastern Europe carried out widespread mass shootings, and up to two million people were killed in this way. In Germany itself, many disabled, homosexual, and "undesirables" were also killed or euthanized as part of a wider eugenics program, which aimed to "purify" German society.

The Holocaust Of all races, the Nazi's viewed Jews as being the most inferior. Conspiracy theories involving Jews go back for centuries in Europe, and they have been repeatedly marginalized throughout history. German fascists used the Jews as scapegoats for the economic struggles during the interwar period. Following Hitler's ascendency to the Chancellorship in 1933, the German authorities began constructing concentration camps for political opponents and so-called undesirables, but the share of Jews being transported to these camps gradually increased in the following years, particularly after Kristallnacht (the Night of Broken Glass) in 1938. In 1939, Germany then invaded Poland, home to Europe's largest Jewish population. German authorities segregated the Jewish population into ghettos, and constructed thousands more concentration and detention camps across Eastern Europe, to which millions of Jews were transported from other territories. By the end of the war, over two thirds of Europe's Jewish population had been killed, and this share is higher still when one excludes the neutral or non-annexed territories.

Lebensraum Another key aspect of Nazi ideology was that of the Lebensraum (living space). Both the populations of the Soviet Union and United States were heavily concentrated in one side of the country, with vast territories extending to the east and west, respectively. Germany was much smaller and more densely populated, therefore Hitler aspired to extend Germany's territory to the east and create new "living space" for Germany's population and industry to grow. While Hitler may have envied the U.S. in this regard, the USSR was seen as undeserving; Slavs were the largest major group in the east and the Nazis viewed them as inferior, which was again used to justify the annexation of their land and subjugation of their people. As the Germans took Slavic lands in Poland, the USSR, and Yugoslavia, ethnic cleansings (often with the help of local conspirators) became commonplace in the annexed territories. It is also believed that the majority of Soviet prisoners of war (PoWs) died through starvation and disease, and they were not given the same treatment as PoWs on the western front. The Soviet Union lost as many as 27 million people during the war, and 10 million of these were due to Nazi genocide. It is estimated that Poland lost up to six million people, and almost all of these were through genocide.

Throughout the 19th century, what we know today as Poland was not a united, independent country; apart from a brief period during the Napoleonic Wars, Polish land was split between the Austro-Hungarian, Prussian (later German) and Russian empires. During the 1800s, the population of Poland grew steadily, from approximately nine million people in 1800 to almost 25 million in 1900; throughout this time, the Polish people and their culture were oppressed by their respective rulers, and cultural suppression intensified following a number of uprisings in the various territories. Following the outbreak of the First World War, it is estimated that almost 3.4 million men from Poland served in the Austro-Hungarian, German and Russian armies, with a further 300,000 drafted for forced labor by the German authorities. Several hundred thousand were forcibly resettled in the region during the course of the war, as Poland was one of the most active areas of the conflict. For these reasons, among others, it is difficult to assess the extent of Poland's military and civilian fatalities during the war, with most reliable estimates somewhere between 640,000 and 1.1 million deaths. In the context of present-day Poland, it is estimated that the population fell by two million people in the 1910s, although some of this was also due to the Spanish Flu pandemic that followed in the wake of the war.

Poland 1918-1945

After more than a century of foreign rule, an independent Polish state was established by the Allied Powers in 1918, although it's borders were considerably different to today's, and were extended by a number of additional conflicts. The most significant of these border conflicts was the Polish-Soviet War in 1919-1920, which saw well over 100,000 deaths, and victory helped Poland to emerge as the Soviet Union's largest political and military rival in Eastern Europe during the inter-war period. Economically, Poland struggled to compete with Europe's other powers during this time, due to its lack of industrialization and infrastructure, and the global Great Depression of the 1930s exacerbated this further. Political corruption and instability was also rife in these two decades, and Poland's leadership failed to prepare the nation for the Second World War. Poland had prioritized its eastern defenses, and some had assumed that Germany's Nazi regime would see Poland as an ally due to their shared rivalry with the Soviet Union, but this was not the case. Germany invaded Poland on September 1, 1939, in the first act of the War, and the Soviet Union launched a counter invasion on September 17; Germany and the Soviet Union had secretly agreed to do this with the Molotov-Ribbentrop Pact in August, and had succeeded in taking the country by September's end. When Germany launched its invasion of the Soviet Union in 1941 it took complete control of Poland, which continued to be the staging ground for much of the fighting between these nations. It has proven difficult to calculate the total number of Polish fatalities during the war, for a variety of reasons, however most historians have come to believe that the figure is around six million fatalities, which equated to almost one fifth of the entire pre-war population; the total population dropped by four million throughout the 1940s. The majority of these deaths took place during the Holocaust, which saw the Nazi regime commit an ethnic genocide of up to three million Polish Jews, and as many as 2.8 million non-Jewish Poles; these figures do not include the large number of victims from other countries who died after being forcefully relocated to concentration camps in Poland.

Post-war Poland

The immediate aftermath of the war was also extremely unorganized and chaotic, as millions were forcefully relocated from or to the region, in an attempt to create an ethnically homogenized state, and thousands were executed during this process. A communist government was quickly established by the Soviet Union, and socialist social and economic policies were gradually implemented over the next decade, as well as the rebuilding, modernization and education of the country. In the next few decades, particularly in the 1980s, the Catholic Church, student groups and trade unions (as part of the Solidarity movement) gradually began to challenge the government, weakening the communist party's control over the nation (although it did impose martial law and imprison political opponent throughout the early-1980s). Increasing civil unrest and the weakening of Soviet influence saw communism in Poland come to an end in the elections of 1989. Throughout the 1990s, Poland's population growth stagnated at around 38.5 million people, before gradually decreasing since the turn of the millennium, to 37.8 million people in 2020. This decline was mostly due to a negative migration rate, as Polish workers could now travel more freely to Western Europea...

Estimates for the total death count of the Second World War generally range somewhere between 70 and 85 million people. The Soviet Union suffered the highest number of fatalities of any single nation, with estimates mostly falling between 22 and 27 million deaths. China then suffered the second greatest, at around 20 million, although these figures are less certain and often overlap with the Chinese Civil War. Over 80 percent of all deaths were of those from Allied countries, and the majority of these were civilians. In contrast, 15 to 20 percent were among the Axis powers, and the majority of these were military deaths, as shown in the death ratios of Germany and Japan. Civilian deaths and atrocities It is believed that 60 to 67 percent of all deaths were civilian fatalities, largely resulting from war-related famine or disease, and war crimes or atrocities. Systematic genocide, extermination campaigns, and forced labor, particularly by the Germans, Japanese, and Soviets, led to the deaths of millions. In this regard, Nazi activities alone resulted in 17 million deaths, including six million Jews in what is now known as The Holocaust. Not only was the scale of the conflict larger than any that had come before, but the nature of and reasoning behind this loss make the Second World War stand out as one of the most devastating and cruelest conflicts in history. Problems with these statistics Although the war is considered by many to be the defining event of the 20th century, exact figures for death tolls have proven impossible to determine, for a variety of reasons. Countries such as the U.S. have fairly consistent estimates due to preserved military records and comparatively few civilian casualties, although figures still vary by source. For most of Europe, records are less accurate. Border fluctuations and the upheaval of the interwar period mean that pre-war records were already poor or non-existent for many regions. The rapid and chaotic nature of the war then meant that deaths could not be accurately recorded at the time, and mass displacement or forced relocation resulted in the deaths of many civilians outside of their homeland, which makes country-specific figures more difficult to find. Early estimates of the war’s fatalities were also taken at face value and formed the basis of many historical works; these were often very inaccurate, but the validity of the source means that the figures continue to be cited today, despite contrary evidence.

In comparison to Europe, estimate ranges are often greater across Asia, where populations were larger but pre-war data was in short supply. Many of the Asian countries with high death tolls were European colonies, and the actions of authorities in the metropoles, such as the diversion of resources from Asia to Europe, led to millions of deaths through famine and disease. Additionally, over one million African soldiers were drafted into Europe’s armies during the war, yet individual statistics are unavailable for most of these colonies or successor states (notably Algeria and Libya). Thousands of Asian and African military deaths went unrecorded or are included with European or Japanese figures, and there are no reliable figures for deaths of millions from countries across North Africa or East Asia. Additionally, many concentration camp records were destroyed, and such records in Africa and Asia were even sparser than in Europe. While the Second World War is one of the most studied academic topics of the past century, it is unlikely that we will ever have a clear number for the lives lost in the conflict.