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.

Russian estimates suggest that the total population of the Soviet Union in 1941 was 195.4 million people, before it fell to 170.5 million in 1946 due to the devastation of the Second World War. Not only did the USSR's population fall as a consequence of the war, but fertility and birth rates also dropped due to the disruption. Hypothetical estimates suggest that, had the war not happened and had fertility rates remained on their pre-war trajectory, then the USSR's population in 1946 would have been 39 million higher than in reality. Gender differences When it comes to gender differences, the Soviet male population fell from 94 million in 1941, to 74 million in 1946, and the female population fell from 102 to 96 million. While the male and female population fell by 19 and 5.5 million respectively, hypothetical estimates suggest that both populations would have grown by seven million each had there been no war. In actual figures, adult males saw the largest change in population due to the war, as a drop of 18 to 21 percent was observed across the three age groups. In contrast, the adult female population actually grew between 1941 and 1946, although the population under 16 years fell by a number similar to that observed in the male population due to the war's impact on fertility.

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.

Throughout the Cold War, the United States and the Soviet Union had relatively similar total populations. The U.S.' population grew from around 205 million to almost 250 million people between 1970 and 1990, while the USSR's population grew from around 240 to 290 million in this time. In these years, the Soviet Union had the third largest population in the world, and the U.S. had the fourth largest (behind China and India respectively). Despite their similar sizes, these populations differed in terms of distribution as the U.S.' population was approximately three quarters urban in this period, whereas the Soviet Union's urban population was just 56 percent in 1970 and 66 percent in 1989. Additionally, the Soviet Union's population was much younger than that of the U.S. due to a higher birth rate and lower life expectancy.

The Second World War had a profound impact on gender ratios within the Soviet Union's population, and its effect on different age groups varied greatly. The Soviet population structure had already been shaped heavily by the First World War, the Russian Revolution, and the famines of the early 1920s and early 1930s. The impact of these events on mortality and fertility meant that, in 1941, the generations whose births corresponded with these events had a lower population than would be expected on a typical population model. For example, in 1941, those aged between 5 and 9 had a significantly lower population than those aged 10 to 14, due to the effects of the Soviet famine of 1932-1933. Additionally, women outnumbered men in all age groups except the very youngest, due to the disproportionate effect of conflict and infant mortality on male populations. Impact of WWII In order to observe the impact of the war, one must compare populations of specific age groups in 1941 with the following age group in 1946. For men of "fighting age" in 1941, i.e. those aged between 15 and 44, these populations experience the most substantial decrease over the course of the war. For example, there are 5.6 million men aged 15-19 in 1941, but just 3.5 million aged 20-24 in 1946, giving a decrease of 38 percent. This decrease of almost forty percent can be observed until the 45-49 group, where the difference is 25 percent. Additionally, women aged between 15 and 34 saw a disproportionate decrease in their populations over this period, as many enlisted in the army and took an active part in the conflict, most notably as medics, snipers, and pilots.

The war's impact on fertility and child mortality meant that, in 1946, the total population under four years old was less than half its size in 1941. Generally, variations between age groups then fluctuated in line with pre-war patterns, however the overall ratio of women to men increased further after the war. For all age groups over 20 years, the number of men decreased between these years, whereas all women's age groups over 30 years saw an increase; this meant that, despite the war, women over 30 had a higher life expectancy in 1946.

One aim of the Soviet Union, and communist countries in general, was to achieve full employment. Official policy was designed to prevent unemployment, and the state stopped paying most unemployment benefits in the 1930s. Every citizen had the right (or requirement) to work, and jobs were allocated by the state, not competed for as they were in the west. People could apply for certain positions, based on their education, experience, or interests, but roles could often be distributed to meet employment demands, or preferential roles were distributed via nepotism. The socialist economic system removed job market competition, which provided increased job security but removed many of the incentives that boosted productivity (especially in later decades). In the 1970s and 1980s, average work weeks were under 35 hours long and people retired in their mid to late fifties. Compared to the U.S. in 1985, on average, work weeks were around four hours shorter in the USSR, and Soviet men retired five years earlier, while women retired nine years earlier than their American counterparts.

Wages In earlier years, wages had been tied to individual performance or output, however the de-Stalinization process of the 1960s introduced a more standardized system of payment; from this point onwards, base wages were more fixed, and bonuses had a larger impact on disposable income. Personal finances in the Soviet Union were very different from those in the west; wages were split into base salaries and bonuses, along with a social wage that was "paid" in the form of investments in housing, healthcare, education, and infrastructure, as well as subsidized vouchers for holidays and food. Many of these amenities were also provided by the state, which removed the individual costs that were required across the west and in post-Soviet states today. Overall, income and money in general had a much lower influence on daily life in the USSR than it did in the west, lessening factors such as financial stress and indebtedness, but restricting consumeristic freedom.

Gender differences A major difference between the East and West Blocs was the participation rate of women in the workforce. Throughout most of the USSR's history, women made up the majority of the workforce, with a 51.4 percent share in 1970, and 50.4 percent in 1989; in the U.S. figures for these years were 38 and 45 percent respectively. Although this was due to the fact that women also made up a larger share of the total population (around 53 percent in this period), Soviet women were possibly the most economically active in the world in these decades. When comparing activity rates of women aged between 40 and 44 across Europe in 1985, the USSR had a participation rate of 97 percent; this was the highest in the East Bloc (where rates ranged from 85 to 93 percent in other countries), and is much higher than rates in Northern Europe (71 percent), Western Europe (56 percent) and Southern Europe (37 percent).

In Russia, the crude birth rate in 1840 was just over 48 live births per thousand people, meaning that approximately 4.8 percent of the population had been born in that year. Throughout the nineteenth century, Russia's crude birth rate remained between 48 and 52, and fell to 43.4 in the late 1920s. From 1930 to 1945, the Soviet Union's crude birth rate dropped greatly, from 43.4 to 18.2, as a result of the Second World War (although it did increase in the late 1930s, in the early stages of the war). Russia did experience a baby boom after the war, and the birth rate did not fall to its pre-war level gain until the late 1960s. From 1970, the birth rate increased slightly to 16.2 in 1990, before the end of communism and dissolution of the Soviet Union caused the crude birth rate to fall to its lowest recorded level over the next decade, to 8.9 in 2000. Since the turn of the millennium, the crude birth rate of Russia has increased steadily, and was expected to be 12.8 in 2020.

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.

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.

The fertility rate of a country is the average number of children that women from that country will have throughout their reproductive years. From 1840 until 1910, Russia's fertility rate was relatively consistent, remaining between 6.7 and 7.4 children per woman during this time. Between 1910 and 1920, the fertility rate drops sharply as a result of the First World War and Russian Revolution (for individual years of WWI, the fertility rate dropped as low as 3.4). From 1920 to 1930 the fertility rate returns above 6 again, however a gradual decline then begins, and by the end of the Second World War, the Russian segment of the Soviet Union's fertility rate was below 2. The population experienced a relatively small 'baby boom' in the two decades following the war, but then the fertility rate dropped again, most sharply between 1990 and 1995 at the end of the Soviet Union's reign. Russia's fertility rate reached its lowest point in 2000 when it fell to just 1.25 children per woman, but in the past two decades it has risen again, and is expected to reach 1.8 in 2020.

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...

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.

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.

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.

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.

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 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...

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.

The Second World War severely altered the demographic composition of many countries, particularly in terms of gender ratios across certain age groups. For age groups below 14 years, there is little observable impact of the war on gender ratios, however, some countries see a drastic change across older generations, particularly in the Soviet Union. For men in their twenties (i.e. those in their late-teens or early-twenties when the war began), the ratio drops from 98 men per 100 women in the 15-19 age group, to 68 men per 100 women in the 25-29 group.

In addition to the Second World War, these figures are affected by trends in nature and other historical events. For example, women tend to have higher overall life expectancies than men, which typically sees gender ratios widen among older generations. The impact of the First World War is also most-observable in France's gender ratios for those aged in their fifties. Additionally, the gap in ratios remains high for the Soviet Union across older age groups due to the impact of the First World War and the famine of the early 1930s, however the figures for Russia itself are even lower as it was disproportionately affected by the Russian Revolution and famine of the 1920s.

From 1800 until the late twentieth century, there was a steady increase in Afghanistan's population. Throughout the nineteenth century, Afghanistan became a battleground for the British Empire, who tried to control the area in order to prevent Russian expansion towards the British Raj. Despite resisting the British invasion in the first Anglo-Afghan War, (where the British Army was almost completely wiped out), the Second Anglo-Afghan War in 1880 saw Britain seize control of the region. In contrast to the neighboring colonies on the Indian subcontinent, Britain did not colonize Afghanistan for economic purposes, therefore they did not invest in agriculture or infrastructure, nor introduce medicine in the same way they did in the Raj, and focused only on Afghanistan's international affairs. Independence and progress The Third Anglo-Afghan War, where Afghan forces invaded British India in 1919, resulted in Afghanistan's independence finally being declared after two months of conflict. The next decade saw some major reforms that attempted to modernize Afghan society, (notable progress was made for women's rights and education) however this alienated many conservative and religious tribes, and a civil war broke out in 1928. After the war (and brief usurpation) the new King of Afghanistan, Nadir Khan, consolidated power, and also moved to modernize the country, but more gradually than his predecessors in order to avoid further alienation and conflict. Khan's approach remained in place until the 1970s, when a bloodless coup established a republic. The republic never achieved political stability, and the Sauri Revolution of 1978 resulted in the formation of the communist Democratic Republic of Afghanistan. Continuous war Despite some progressive reforms, such as banning forced marriages and opening a space for women in politics, the determination to promote state atheism combined with the country's economic dependence on the Soviet Union led to serious opposition from Afghan people, particularly in rural areas. On December 24, 1979, the Soviet Union (backed by the Afghan government) invaded the country, and the ensuing decade-long guerilla war resulted in as many as two million fatalities and three million wounded, as well as two million internally displaced persons and five million refugees abroad. Soviet withdrawal was seen as a western victory, as they had supported the Taliban in their fight against the Soviets, however a decade later the Taliban refused to hand over Osama Bin Laden and other al-Qaeda suspects to the US, following the 9/11 attacks in 2001. This led to US and British forces launching Operation Enduring Freedom in October 2001, and an intensive bombing campaign followed, destroying many major cities in the country. The Taliban government was toppled in December 2001, and in 2002 a western-led rebuilding of the country began. Over the past two decades, many displaced Afghans have returned home, leading to some economic growth, however guerilla fighting continues and there is a strong military presence in the country (including many Taliban controlled areas). In 2020, Afghanistan remains one of the poorest and most politically unstable countries in the world, however the rapid population growth experienced in recent decades is expected to continue well into the future, as improvements in medical care and humanitarian aid become more widespread across the country.