From 1273 until 1918, Austria was the seat of power of the House of Habsburg; one of Europe's most powerful and influential royal families of the past millennium. During this time and in the subsequent century since the Austro-Hungarian Empire's dissolution, the borders and demography of the Austrian state have changed dramatically, with the population growing from approximately three million people in 1800 to just over nine million in 2020. The area of modern Austria's population rose gradually throughout the nineteenth century, until the early 1900s, where it then dropped and fluctuated during the World Wars, before rising again until recent years.

End of an empire

The assassination of the heir to the Austrian throne, Archduke Franz Ferdinand, in Sarajevo on June 28, 1914, caused Austria to declare war on Serbia, which marked the outbreak of the First World War. The war (and subsequent Spanish Flu pandemic) would see the deaths of more than 1.2 million people from the Austro-Hungarian Empire, and the area of modern Austria's population dropped by almost 400,000 people between 1916 and 1920. In the years preceding the First World War, Slavic nationalism and tensions between various ethnicities in the empire had escalated to a new level; following the dissolution of Austria-Hungary in 1918, new states such as Poland, Czechoslovakia and Yugoslavia were created for corresponding ethnic groups, while Austrian and Hungarian states were created for ethnic Germans and Magyars respectively (Austria still uses this border today). The Treaty of Versailles had forbidden Austria from joining Germany, however in 1938, German Chancellor Adolf Hitler (who was born in Austria) united the two nations as part of the German Third Reich, with overwhelming support by the people of Austria. In the next few years, Austria's population decreased slightly, as a result of the forced relocation of Jews and the outbreak of the Second World War. Due to the Austria-German union, separate records were not kept for Austrian and German deaths during the war, however most estimates put Austria's total at over 350,000 fatalities.

Post-war Austria

Following Germany's defeat, Austria was split into four separately administered sections, and then the Second Austrian Republic was established in 1955, declaring its permanent neutrality in foreign affairs. In the period after this Austria has enjoyed a period of continued prosperity with a high standard of living and reasonable economic growth. Population growth stagnated in the 80's with the legalization of abortion and improved access to contraception, but has grown steadily in the past three decades. Austria is consistently ranked among the top 20 richest countries in the world in terms of GDP per capita, and in 2018 it was ranked 20th in the world by the Human Development Index.

Austria: Cisleithania was the Austrian-ruled section of the Austro-Hungarian Empire. This graphic shows the total population of Austria: Cisleithania from 1818 until 1910, just before the outbreak of World War I. As we can see from the graph, the population grows rather gradually throughout this 92 year period. The only dip in population comes between 1846 and 1851, possibly as a result of the revolutions that took place in 1848. After this time the population continues to grow before reaching over 28.5 million people in 1910.

The later stages of the Austro-Hungarian Empire's history were marked by a period of internal tensions between the varying ethnic groups, as the ethnic Slavs, Czechs and Romance groups felt oppressed by the ruling Germanic and Magyar peoples. The Empire was then dissolved in 1918 following its defeat during the First World War, and a number of new states were formed in the aftermath.