In Soviet Russia (RSFSR) in 1939 and 1959, ethnic Russians made up the largest share of the total population, with a share of approximately 83 percent. Tatars were the second largest ethnic group, followed by Ukrainians. Russians were consistently the largest ethnic group in the Soviet Union as a whole, with an overall share of 53 percent in 1979.

Due to the devastating impact of the Second World War on the Soviet population, the total population in 1950 was almost 15.5 million fewer than in 1940, which is a decrease of eight percent. In Russia (RSFSR), the largest of the Soviet states, the population difference was almost nine million people; also eight percent. It would take until 1955 for the populations of either the USSR or Russia to reach their pre-war levels, which was a decade after the conflict had ended. Urbanization Despite this drop in total population, industrialization and urbanization saw a significant change in the USSR's population distribution between the given years. The Soviet urban population increased by 6.3 million, or ten percent, between 1940 and 1950; 5.8 million of this was in Russia, which was a 15 percent increase. In contrast, the Soviet Union's rural population dropped by 21.8 million (a 17 percent change), 14.5 million of which in Russia (a decrease of 20 percent). In terms of overall population, the urban population of the USSR rose from 33 to 39 percent between 1940 and 1950, and from 34 to 43 percent in Russia. By 1955, 44 percent of the Soviet population, and 49 percent of the Russian population, lived in an urban setting.

Over the course of the Second World War, approximately 44.5 percent of the Soviet population and 8.7 of Soviet territory was occupied by the Axis forces at some point. Despite being allied in the war's early stages, with both countries invading Poland in 1939 via the Molotov-Ribbentrop Pact, Germany would launch Operation Barbarossa, the invasion of the USSR, in 1941, which would become the largest military invasion in history. Movement of the Eastern Front The surprise invasion began on June 22, and Axis forces caught the Soviets off-guard, quickly pushing their way eastward along a frontline that stretched from the Baltic to Black seas. The length of the front-line allowed Axis forces to execute pincer movements around cities and strongholds, which cut off large numbers of Soviet soldiers from their supply lines, as well as preventing reinforcements; in this process millions of Soviet troops were taken as prisoner. Within three weeks, the Germans had taken much of present-day Poland, Belarus, and the Baltic states, before taking Moldova and Ukraine in September, and pushing into western Russia between September and December. The front lines had reached the outskirts of Moscow by November, before exhaustion and cold weather helped Soviet forces hold the line and stall the German offensive. The Red Army was then able to regroup and turning the Germans' own tactics against them, using two-pronged attacks to encircle large numbers of troops, although harsh weather made this stage of the conflict much slower.

The lines remained fairly static until mid-1942, when the Germans focused their offensive on the south, concentrating on the Caucasian oil fields and the Volga River. By November 1942, Axis forces had pushed into these regions, establishing what would ultimately be the largest amount of occupied Soviet territory during the war. Once again, winter halted the Axis advance, and allowed the Red Army to regroup. Learning from the previous year, the Axis command strengthened their forces near Moscow in anticipation of the Soviet counter-offensive, but were caught off-guard by a second counter-offensive in the south, most famously at Stalingrad. The Battle of Stalingrad would come to epitomize the extreme loss, destruction, and brutality of war on the eastern front, with conflict continuing in the city months after the rest of the Axis forces had been pushed west. As 1943 progressed, the Red Army gained momentum by targeting inferiorly-trained and equipped non-German regiments. The spring then became something of a balancing act for the Axis powers, as the Soviets consistently attacked weak points, and German regiments were transferred to reinforce these areas. In the summer of 1943, the front line was static once more, however the momentum was with the Soviets, who were able to capitalize on victories such as Kursk and gradually force the Axis powers back. By 1944, the Red Army had re-captured much of Ukraine, and had re-taken the south by the summer. When the Western Allies arrived in France in June, the Soviets were already pushing through Ukraine and Belarus, towards Berlin. In August 1944, the last Axis forces were pushed out of Soviet territory, and Soviet forces continued their push towards the German capital, which fell in May 1945. Soviet death toll In addition to the near-five million Soviet troops who died during Operation Barbarossa, millions of civilians died through starvation, areal bombardment, forced labor, and systematic murder campaigns. Due to the nature and severity of Soviet losses, total figures are difficult to estimate; totals of 15-20 million civilians and 7-9 million military deaths are most common. Further estimates suggest that the disruption to fertility, in addition to the high death toll, meant that the USSR's population in 1946 was 40 million lower than it would have been had there been no war.

In 1938, the year before the outbreak of the Second world War, the countries with the largest populations were China, the Soviet Union, and the United States, although the United Kingdom had the largest overall population when it's colonies, dominions, and metropole are combined. Alongside France, these were the five Allied "Great Powers" that emerged victorious from the Second World War. The Axis Powers in the war were led by Germany and Japan in their respective theaters, and their smaller populations were decisive factors in their defeat. Manpower as a resource In the context of the Second World War, a country or territory's population played a vital role in its ability to wage war on such a large scale. Not only were armies able to call upon their people to fight in the war and replenish their forces, but war economies were also dependent on their workforce being able to meet the agricultural, manufacturing, and logistical demands of the war. For the Axis powers, invasions and the annexation of territories were often motivated by the fact that it granted access to valuable resources that would further their own war effort - millions of people living in occupied territories were then forced to gather these resources, or forcibly transported to work in manufacturing in other Axis territories. Similarly, colonial powers were able to use resources taken from their territories to supply their armies, however this often had devastating consequences for the regions from which food was redirected, contributing to numerous food shortages and famines across Africa, Asia, and Europe. Men from annexed or colonized territories were also used in the armies of the war's Great Powers, and in the Axis armies especially. This meant that soldiers often fought alongside their former-enemies. Aftermath The Second World War was the costliest in human history, resulting in the deaths of between 70 and 85 million people. Due to the turmoil and destruction of the war, accurate records for death tolls generally do not exist, therefore pre-war populations (in combination with other statistics), are used to estimate death tolls. The Soviet Union is believed to have lost the largest amount of people during the war, suffering approximately 24 million fatalities by 1945, followed by China at around 20 million people. The Soviet death toll is equal to approximately 14 percent of its pre-war population - the countries with the highest relative death tolls in the war are found in Eastern Europe, due to the intensity of the conflict and the systematic genocide committed in the region during the war.

The Second World War's Eastern Front, the largest theater of war in history, was largely dominated by the conflict between Germany and the Soviet Union. The two countries had agreed upon an unexpected peace pact in 1939, with the joint invasion and partition of Poland, but this peace was broken in June 1941 when Germany invaded the Soviet Union during Operation Barbarossa. Germany's economic and technological superiority, alongside its Blitzkrieg military strategy, allowed it to gain the upper hand in the early stages of the conflict. Within six months the Germans had pushed the frontlines back to Moscow, and almost 40 percent of the Soviet population now lived in occupied territory. German gains at the expense of the Soviets was reflected in the changing balance of their economies - Germany's GDP grew each year until 1944, whereas the Soviet GDP fell by one third between 1940 and 1942.

Over the course of the long nineteenth century, Estonia's population almost tripled, from 0.33 million in 1800, to over one million at the outbreak of the First World War. Throughout this time, Estonia was a part of the Russian Empire, however Germany then annexed the region during the First World War; when the German army eventually retreated in 1918, Estonian forces prevented Russia from re-taking the area in the Estonian War of Independence, and an independent Estonian Republic was gradually established between 1918 and 1920. Relative to its size and population, Estonia developed into a prosperous and peaceful nation in the interwar period, and Estonian language and culture thrived, although political stability proved difficult for the Baltic state.

Estonia in WWII Estonia's independence was short lived, as the country was then annexed by the Soviet Union as part of the secret Molotov-Ribbentrop Pact between Germany and the Soviets. The invasion was achieved with little-to-no conflict, as Estonia capitulated when faced with the vastly superior military and navy of the Soviet Union. Annexation became official in June 1940; a puppet, communist government was quickly established, and many military and political rivals were imprisoned or executed under Soviet control. When Germany invaded the Soviet Union the following year, they quickly took control of Estonia, but simply replaced the Soviet Union's rule with their own, and did not grant re-establish sovereignty as many Estonians had expected or hoped for. By the war's end, Estonia suffered approximately 83,000 deaths at the hands of the Soviet Union and Germany, with almost 50,000 of these civilian deaths, and the rest were fatalities of Estonian soldiers who were forced to fight in other nations' armies.

Post-war Estonia Following the war, Estonia remained under Soviet control, and between 1950 and 1990, the population of Estonia grew steadily, from 1.1 million to almost 1.6 million. In the wake of the Soviet Union's collapse, Estonia established a rapid, but peaceful independence in 1991; and the population dropped by roughly ten percent by the end of the century. This was mostly due to non-Estonians returning to their country or region of origin, although a wave of Estonian emigration soon followed. Estonia joined the European Union in 2004, and from 2000 until 2015, Estonia's population continued to fall, reaching just 1.3 million people in 2015. Recent years, however, have seen a reversal in this trend, with limited growth since 2015; although demographers predict that Estonia's population will drop below one million people in the next half-century. The past three decades have marked the longest continuous period in the past 800 years, where the region of Estonia was not under German, Polish, Russian or Scandinavian control.

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 European countries in search of work, facilitated by Pola...

It is estimated that the Second World War was responsible for the deaths of approximately 3.76 percent of the world's population between 1939 and 1945. In 2022, where the world's population reached eight billion, this would be equal to the death of around 300 million people.

The region that experienced the largest loss of life relative to its population was the South Seas Mandate - these were former-German territories given to the Empire of Japan through the Treaty of Versailles following WWI, and they make up much of the present-day countries of the Marshall Islands, Micronesia, the Northern Mariana Islands (U.S. territory), and Palau. Due to the location and strategic importance of these islands, they were used by the Japanese as launching pads for their attacks on Pearl Harbor and in the South Pacific, while they were also taken as part of the Allies' island-hopping strategy in their counteroffensive against Japan. This came at a heavy cost for the local populations, a large share of whom were Japanese settlers who had moved there in the 1920s and 1930s. Exact figures for both pre-war populations and wartime losses fluctuate by source, however civilian losses in these islands were extremely high as the Japanese defenses resorted to more extreme measures in the war's final phase.

This graph shows the total population of Estonia, Latvia and Lithuania in the years between 1922 and 1935, as well as the total number of males and females. After the First World War the Baltic states began claiming their independence from tsarist Russia, as the events of the Russian Revolution took place. Inter-war Estonia The Estonian War of Independence from 1918 to 1920 led to the country's first period of independence, until it became occupied by the Soviet Union again in 1940 during the Second World War. After Estonia gained independence the country experienced a period of political turmoil, including a failed coup d'etat in 1924, and was hit hard by the Great Depression in 1929 before things became more stable in the mid 1930s. Between 1939 and 1945 Estonia's population was devastated by the Second World War, with some estimates claiming that as many as 7.3 percent of all civilians perished as a result of the conflict. From the graph we can see the population grew by 119 thousand people during the 12 years shown, growing from 1.107 million to 1.126 million. The number of women was also higher than the number of men during this time, by 67 thousand in 1922 and 68 thousand in 1934. Inter-war Latvia For Latvia, Independence was a hard-won struggle that had devastated the population in the late 1910s. Similarly to Estonia, the advent of independence brought many challenges to Latvia, and a period of political and economic turmoil followed, which was exacerbated by the Great Depression in 1929. After economic recovery began in 1933, and a coup d'etat established stricter control in 1934, the Latvian economy and political landscape became more stable and the quality of life improved. This lasted until the Second World War, where Latvia became one of the staging grounds of Germany's war against Soviet Russia, and approximately 12.5 percent of all civilians died. From the data we can see that Latvia's population between 1925 and 1935 grew steadily by 95,000 in this decade, with the number of men and women growing at a similar rate. Inter-war Lithuania Lithuania's experience in the interwar period was slightly different to that of Latvia and Estonia. The end of the First World War led to a growing movement for independence from German, Russian or Polish influence, however these countries were reluctant to cede control to one another, and independence was finally achieved in 1922. A right wing dictatorship was established in 1926, which maintained political and civil control until the outbreak of the Second World War, however interference from other nations, particularly Germany, was ever-present in Lithuanian economic activity. From the graph we have only one set of figures, showing that the Lithuanian population was just over 2 million in 1929, with approximately 5 percent more women than men. World War II again devastated Lithuania's population, with almost 14.4 percent of the entire population falling during the conflict.

During the Second World War, the three Axis powers of Germany, Italy, and Finland mobilized the largest share of their male population. For the Allies, the Soviet Union mobilized the largest share of men, as well as the largest total army of any country, but it was restricted in its ability to mobilize more due to the impact this would have on its economy. Other notable statistics come from the British Empire, where a larger share of men were drafted from Dominions than from the metropole, and there is also a discrepancy between the share of the black and white populations from South Africa.

However, it should be noted that there were many external factors from the war that influenced these figures. For example, gender ratios among the adult populations of many European countries was already skewed due to previous conflicts of the 20th century (namely WWI and the Russian Revolution), whereas the share of the male population eligible to fight in many Asian and African countries was lower than more demographically developed societies, as high child mortality rates meant that the average age of the population was much lower.

In 1940, the Soviet Union produced significantly less industrial material than the United States in terms of natural resources and construction materials. The same was true when compared with Germany, apart from iron and steel; the USSR produced over double the amount of iron ore as Germany, and a similar amount of cast iron and steel. However, while the U.S. and Soviet populations were more comparable in 1940, Germany's population was around 70 million, which was 100 million fewer than the USSR; therefore the difference in per capita output was even higher in Germany than what is shown in the graph.

In 1800, the region of Germany was not a single, unified nation, but a collection of decentralized, independent states, bound together as part of the Holy Roman Empire. This empire was dissolved, however, in 1806, during the Revolutionary and Napoleonic eras in Europe, and the German Confederation was established in 1815. Napoleonic reforms led to the abolition of serfdom, extension of voting rights to property-owners, and an overall increase in living standards. The population grew throughout the remainder of the century, as improvements in sanitation and medicine (namely, mandatory vaccination policies) saw child mortality rates fall in later decades. As Germany industrialized and the economy grew, so too did the argument for nationhood; calls for pan-Germanism (the unification of all German-speaking lands) grew more popular among the lower classes in the mid-1800s, especially following the revolutions of 1948-49. In contrast, industrialization and poor harvests also saw high unemployment in rural regions, which led to waves of mass migration, particularly to the U.S.. In 1886, the Austro-Prussian War united northern Germany under a new Confederation, while the remaining German states (excluding Austria and Switzerland) joined following the Franco-Prussian War in 1871; this established the German Empire, under the Prussian leadership of Emperor Wilhelm I and Chancellor Otto von Bismarck. 1871 to 1945 - Unification to the Second World War The first decades of unification saw Germany rise to become one of Europe's strongest and most advanced nations, and challenge other world powers on an international scale, establishing colonies in Africa and the Pacific. These endeavors were cut short, however, when the Austro-Hungarian heir apparent was assassinated in Sarajevo; Germany promised a "blank check" of support for Austria's retaliation, who subsequently declared war on Serbia and set the First World War in motion. Viewed as the strongest of the Central Powers, Germany mobilized over 11 million men throughout the war, and its army fought in all theaters. As the war progressed, both the military and civilian populations grew increasingly weakened due to malnutrition, as Germany's resources became stretched. By the war's end in 1918, Germany suffered over 2 million civilian and military deaths due to conflict, and several hundred thousand more during the accompanying influenza pandemic. Mass displacement and the restructuring of Europe's borders through the Treaty of Versailles saw the population drop by several million more.

Reparations and economic mismanagement also financially crippled Germany and led to bitter indignation among many Germans in the interwar period; something that was exploited by Adolf Hitler on his rise to power. Reckless printing of money caused hyperinflation in 1923, when the currency became so worthless that basic items were priced at trillions of Marks; the introduction of the Rentenmark then stabilized the economy before the Great Depression of 1929 sent it back into dramatic decline. When Hitler became Chancellor of Germany in 1933, the Nazi government disregarded the Treaty of Versailles' restrictions and Germany rose once more to become an emerging superpower. Hitler's desire for territorial expansion into eastern Europe and the creation of an ethnically-homogenous German empire then led to the invasion of Poland in 1939, which is considered the beginning of the Second World War in Europe. Again, almost every aspect of German life contributed to the war effort, and more than 13 million men were mobilized. After six years of war, and over seven million German deaths, the Axis powers were defeated and Germany was divided into four zones administered by France, the Soviet Union, the UK, and the U.S.. Mass displacement, shifting borders, and the relocation of peoples based on ethnicity also greatly affected the population during this time. 1945 to 2020 - Partition and Reunification In the late 1940s, cold war tensions led to two distinct states emerging in Germany; the Soviet-controlled east became the communist German Democratic Republic (DDR), and the three western zones merged to form the democratic Federal Republic of Germany. Additionally, Berlin was split in a similar fashion, although its location deep inside DDR territory created series of problems and opportunities for the those on either side. Life quickly changed depending on which side of the border one lived. Within a decade, rapid economic recovery saw West Germany become western Europe's strongest economy and a key international player. In the east, living standards were much lower, although unemployment was almost non-existent; internationally, East Germany was the strongest economy in the Eastern Bloc (after the USSR), though it eventually fell behind the West by the 1970s. The restriction of movement between the two states also led to labor shortages in the West, and an influx of migrants from...

In 1800, the population of Latvia was approximately 591,000, a number which would grow steadily throughout the 19th century as reforms in agrarian law and steady improvements in standards of living and production allowed for a significant expansion in population. However, the population of Latvia would peak at just under 2.5 million in 1909, before falling sharply in the First World War. As the battlefield between the German and Russian Empires, Latvia and the other Baltic states were the site of widespread combat, attacks on civilians, and scorched earth campaigns, devastating the country. Even many of those who did not lose their lives in the war were forced to evacuate under orders from the Russian Empire, leading hundreds of thousands to flea eastward. As a result, by the end of the First World War, the population of Latvia would fall to approximately 1.8 million, and would not recover to pre-war population levels until the 1980s.

Following the end of the First World War, Latvia's population would remain largely stagnant at this level, rising slightly before falling back down in the Second World War. However, population growth would increase rapidly in the post-war years, as rapid industrialization by the Soviet Union and sharp decreases in mortality as mass immunization and vaccination would allow for the population to return to pre-World War levels by the 1980s. Latvia's population would begin to decline rapidly with the dissolution of the Soviet Union, however, as significant unemployment and economic turmoil would lead large numbers of Latvians to migrate west to the European Union in search of work, particularly so following Latvia's inclusion into the Schengen Area in 2003. As a result, in 2020, Latvia is estimated to have a population of just under 1.9 million.

Differences in army sizes and military manpower of nations played a crucial role in the Second World War. While the Allied nations and their colonies or dominions had significantly larger combined populations than the Axis powers, the difference in the number of service personnel at their disposal was much smaller, especially in the war's early phase. Eastern Front With the annexation of Poland, Czechoslovakia, and the Balkans by mid-1941, the Axis forces in the Eastern theater outnumbered the Soviet Union. Following the launch of Operation Barbarossa in June 1941, the Axis forces were then able to push the Soviets as far back as Moscow - when the frontline stabilized, the Soviet Union was able to call upon its larger population to replenish and reinforce its ranks, eventually outnumbering the enemy the following year. Many Soviet women were also drafted in to fight, with notable and decorated examples serving as snipers, pilots, and artillery operators. Western Allies The combined Allied forces in the Pacific and on the Western European fronts (i.e. those mostly led by the UK and U.S.) always outnumbered the Axis powers. This was largely due to the increased mobilization of the United States military after 1941, particularly in the build up to the Invasion of Normandy on June 6, 1944, as well as the redistribution of Germany's forces from the Eastern to Western fronts in response to this, and the withdrawal of Italy from the war in late 1943. Japan did ramp up its conscription efforts in the final years of the war, but it was not enough to offset the huge numerical advantage of the Allies.

Over the course of the Second World War approximately 127.2 million people were mobilized. The world's population in 1940 was roughly 2.3 billion, meaning that between five and six percent of the world was drafted into the military in some capacity. Approximately one in every 25 people mobilized were women, who generally served in an administrative or medical role, although hundreds of thousands of women did see active combat. Largest armies In absolute numbers, the Soviet Union mobilized the largest number of people at just under 34.5 million, and this included roughly 35 percent of the USSR's male population. By the war's end, more Soviets were mobilized than all European Axis powers combined. However, in relative terms, it was Germany who mobilized the largest share of its male population, with approximately 42 percent of men serving. The USSR was forced to find a balance between reinforcing its frontlines and maintaining agricultural and military production to supply its army (in addition to those in annexed territory after 1941), whereas a large share of soldiers taken from the German workforce were replaced by workers drafted or forcibly taken from other countries (including concentration camp prisoners and PoWs). Studying the figures The figures given in these statistics are a very simplified and rounded overview - in reality, there were many nuances in the number of people who were effectively mobilized for each country, their roles, and their status as auxiliary, collaborative, or resistance forces. The British Empire is the only power where distinctions are made between the metropole and its colonies or territories, whereas breakdowns of those who fought in other parts of Asia or Africa remains unclear. Additionally, when comparing this data with total fatalities, it is important to account for the civilian death toll, i.e. those who were not mobilized.

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.

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.

In 1800, the population of the area of modern-day Lithuania was estimated to be just under 780,000. Lithuania’s rate of population growth would remain largely unchanged in the 19th century, as the Russian Empire would slowly but gradually develop its border regions. While large numbers of Lithuanians would emigrate west-ward (largely to the United States) between 1867 and 1868 after a famine in the country, growth would remain largely uninterrupted until the beginning of the First World War in 1912, which would see Lithuania, like much of the Baltic region, devastated as the battleground between the German and Russian Empires. As the conflict spread, those who were not made to evacuate by orders from the Russian government would face economic turmoil under German occupation, and as a result, Lithuania’s population would fall from just under 2.9 million in 1910, to under 2.3 million by 1920.

While Lithuania’s population would start to grow once more following the end of the First World War, this growth would be short-lived, as economic turmoil from the Great Depression, and later occupation and campaigns of mass extermination in the Second World War, most notably the extermination of 95 to 97 percent of the country’s Jewish population in the Holocaust, would cause Lithuania’s population growth to stagnate throughout the 1930s and 1940s. In the years following the end of the Second World War, Lithuania’s population would steadily climb, as industrialization by the Soviet Union would lead to improved economic growth and access to health, and campaigns of mass immunization and vaccination would lead to a sharp decline in child mortality. As a result, by the 1990s, Lithuania would have a population of over 3.7 million. However, Lithuania’s population would rapidly decline in the years following the dissolution of the Soviet Union in 1991, as economic crises and mass emigration from the country, paired with sharp declines in fertility, would result in a dramatic reduction in population. As a result, in 2020, Lithuania is estimated to have a population of just over 2.7 million.

In the build up to the Second World War, the United States was the major power with the highest gross domestic product (GDP) per capita in the world. In 1938, the United States also had the highest overall GDP in the world, and by a significant margin, however differences in GDP per person were much smaller. Switzerland In terms of countries that played a notable economic role in the war, the neutral country of Switzerland had the highest GDP per capita in the world. A large part of this was due to the strength of Switzerland's financial system. Most major currencies abandoned the gold standard early in the Great Depression, however the Swiss Franc remained tied to it until late 1936. This meant that it was the most stable, freely convertible currency available as the world recovered from the Depression, and other major powers of the time sold large amounts of gold to Swiss banks in order to trade internationally. Switzerland was eventually surrounded on all sides by Axis territories and lived under the constant threat of invasion in the war's early years, however Swiss strategic military planning and economic leverage made an invasion potentially more expensive than it was worth. Switzerland maintained its neutrality throughout the war, trading with both sides, although its financial involvement in the Holocaust remains a point of controversy. Why look at GDP per capita? While overall GDP is a stronger indicator of a state's ability to fund its war effort, GDP per capita is more useful in giving context to a country's economic power in relation to its size and providing an insight into living standards and wealth distribution across societies. For example, Germany and the USSR had fairly similar GDPs in 1938, whereas Germany's per capita GDP was more than double that of the Soviet Union. Germany was much more industrialized and technologically advanced than the USSR, and its citizens generally had a greater quality of life. However these factors did not guarantee victory - the fact that the Soviet Union could better withstand the war of attrition and call upon its larger population to replenish its forces greatly contributed to its eventual victory over Germany in 1945.

By mid-1941, Axis forces had already taken control of most of mainland Europe, as well as much of Northern Africa and parts of the Middle East*. At the outbreak of Operation Barbarossa, the major European countries not under Axis control were the officially-neutral states of Ireland, Portugal, Spain, Sweden, Switzerland, and Turkey, while the Soviet Union and United Kingdom were actively at war with the Axis Powers. By mid-1941, Germany and its allies controlled an area of approximately 3.28 million square kilometers in Europe; by comparison, modern Germany covers an area of approximately 357 thousand square kilometers. Axis control of Europe From September 1938, when Germany annexed the Czech Sudetenland, until June 1941, when Germany launched its invasion of the Soviet Union, the Axis Powers spent much of their time and resources consolidating power across Europe. Countries such as Bulgaria, Hungary, Romania, and Finland aligned themselves with Germany, as did Italy, who became one of the chief aggressors around the Mediterranean and in Africa. Germany and the Soviet Union both invaded and partitioned Poland in September 1939, through the Molotov-Ribbentrop Pact of non-aggression to one-another. Germany then took Denmark and most of Norway in April 1940, before pushing into Benelux and France in May. Italy also annexed Albania in April, which was used as a launching point for its failed invasion of Greece later in the year. As Italy had failed to secure the Balkans, a joint Axis offensive then pushed into Yugoslavia and Greece in April 1941, ultimately overwhelming any resistance. However, German intervention in the south then delayed the Axis invasion of the Soviet Union by over a month; Hitler later claimed that this was the reason for Germany's failure to take Moscow before the winter months, although many historians disagree. Launch of Operation Barbarossa Germany broke their pact of non-aggression with the Soviet Union with a surprise invasion, known as Operation Barbarossa, on June 22, 1941. While Axis forces had already extended control over most of Europe by this point, Operation Barbarossa became the largest military invasion or operation in human history. When compared with German capacities in its pre-1938 borders, within a few months of the invasion, the area of land controlled by Germany had grown by a factor of six, the population by a factor of four, and its access to natural resources and energy had also grown several times larger. These increased capacities were essential in allowing Germany to continue its expansion and aggression for the years to come, before the Soviet Union and the Western Allies eventually defeated the Axis forces four years later.