Austria-Hungary in the context of "State of Slovenes, Croats and Serbs"

Yugoslavia was a state concept among the South Slavic intelligentsia and later popular masses from the 19th to early 20th centuries that culminated in its realization after the 1918 collapse of Austria-Hungary at the end of World War I and the formation of the Kingdom of Serbs, Croats and Slovenes. However, from as early as 1922 onward, the kingdom was better known colloquially as Yugoslavia (or similar variants); in 1929 the name was made official when the country was formally renamed the "Kingdom of Yugoslavia".

The creation of Yugoslavia has been described as expansionist and irredentist in its approach to foreign policy, and federalist in its approach to politics, with power centralised in the Serb-dominated government. Despite the idea of Yugoslavism having promoted equality among the South Slavic ethnic groups, the new Yugoslav state was ruled by the Serbian Karađorđević dynasty that sought to implement pro-Serb policies throughout the country, leaving minority groups like Croatians and Bosniaks (Bosnian Muslims) not feeling represented in the new government. This led to the formation of opposition parties that became identified with particular ethnic groups within the country. Similarly, the concept of Yugoslavism became associated with the idea of a South Slavic nation dominated by Serbs; and in some instances, forced cultural assimilation policies introduced by the Serb-led Yugoslav government. However, the creation of Yugoslavia remained popular even among non-Serbs, as it was seen as a means of unification for South Slavs to protect themselves against non-Slavic powers such as Fascist Italy.

The Balkan Wars were two conflicts that took place in the Balkan states in 1912 and 1913. In the First Balkan War, the four Balkan states of Greece, Serbia, Montenegro and Bulgaria declared war upon the Ottoman Empire and defeated it, in the process stripping the Ottomans of their European provinces, leaving only Eastern Thrace under Ottoman control. In the Second Balkan War, Bulgaria fought against the other four combatants of the first war. It also faced an attack from Romania from the north. The Ottoman Empire lost the bulk of its territory in Europe. Although not involved as a combatant, Austria-Hungary became relatively weaker as a much enlarged Serbia pushed for union of the South Slavic peoples. The war set the stage for the July crisis of 1914 and as a prelude to the First World War.

By the early 20th century, Bulgaria, Greece, Montenegro and Serbia had achieved independence from the Ottoman Empire, but large elements of their ethnic populations remained under Ottoman rule. Over the course of the Macedonian Struggle these states fought for influence between themselves and the Ottoman government within Ottoman Macedonia, during which their governments came under the control of nationalists. In 1912, these countries united to formed the Balkan League. The First Balkan War began on 8 October 1912, when the League member states attacked the Ottoman Empire, and ended eight months later with the signing on 30 May 1913 of the Treaty of London negotiated together with the Great Powers. The Great Powers - particularly Italy and Austria-Hungary -- included independence for Albania in the Treaty. The Second Balkan War began on 16 June 1913, when Bulgaria, dissatisfied with its allotment of territory from Macedonia, attacked its former Balkan League allies. The combined forces of the Serbian and Greek armies, with their superior numbers repelled the Bulgarian offensive and counter-attacked by invading Bulgaria from the west and the south. Romania, having taken no part in the first conflict, had intact armies to strike with and invaded Bulgaria from the north in violation of a peace treaty between the two states. The Ottoman Empire also attacked Bulgaria and advanced in Thrace, regaining Adrianople. In the resulting Treaty of Bucharest, Bulgaria managed to retain most of the territories it had gained in the First Balkan War. However, it was forced to cede the ex-Ottoman south part of Dobruja province to Romania.

The Kingdom of Serbia was a country located in the Balkans which was created when the ruler of the Principality of Serbia, Milan I, was proclaimed king in 1882. Since 1817, the Principality was ruled by the Obrenović dynasty (replaced by the Karađorđević dynasty for a short time). The Principality of Serbia, under the suzerainty of the Turkish Empire, de facto achieved full independence when the very last Ottoman troops left Belgrade in 1867. The Congress of Berlin in 1878 recognized the formal independence of the Principality of Serbia, and in its composition Nišava, Pirot, Toplica and Vranje districts entered the South part of Serbia.

In 1882, Serbia was elevated to the status of a kingdom, initially maintaining a foreign policy friendly to Austria-Hungary before turning to the Russian Empire and France following a coup d'état in 1903. Between 1912 and 1913, Serbia greatly enlarged its territory through engagement in the First and Second Balkan Wars – Sandžak-Raška, Kosovo Vilayet and Vardar Macedonia were annexed. At the end of World War I in 1918 it united with Vojvodina and the Kingdom of Montenegro, and in December 1918 it merged with the newly created State of Slovenes, Croats and Serbs to form the Kingdom of Serbs, Croats and Slovenes (later known as Kingdom of Yugoslavia) under the continued rule of the Karađorđević dynasty.

Moravia is a historical region in the east of the Czech Republic and one of three historical Czech lands, with Bohemia and Czech Silesia.

The medieval and early modern Margraviate of Moravia was a crown land of the Lands of the Bohemian Crown from 1348 to 1918, an imperial state of the Holy Roman Empire from 1004 to 1806, a crown land of the Austrian Empire from 1804 to 1867, and a part of Austria-Hungary from 1867 to 1918. Moravia was one of the five lands of Czechoslovakia founded in 1918. In 1928 it was merged with Czech Silesia, and then dissolved in 1948 during the abolition of the land system following the communist coup d'état.

The Anschluss (German: [ˈʔanʃlʊs] , or Anschluß, lit. 'joining' or 'connection'), also known as the Anschluß Österreichs (pronunciation, English: Annexation of Austria), was the annexation of the Federal State of Austria into Nazi Germany on 12 March 1938.

The idea of an Anschluss (a united Austria and Germany that would form a "Greater Germany") arose after the 1871 unification of Germany excluded Austria and the German Austrians from the Prussian-dominated German Empire. It gained support after the Austro-Hungarian Empire fell in 1918. The new Republic of German-Austria attempted to form a union with Germany, but the 1919 Treaty of Saint Germain and Treaty of Versailles forbade both the union and the continued use of the name "German-Austria" (Deutschösterreich); they also stripped Austria of some of its territories, such as the Sudetenland. This left Austria without most of the territories it had ruled for centuries and amid economic crisis.

Adolf Hitler (20 April 1889 – 30 April 1945) was an Austrian-born German politician who was the dictator of Germany during the Nazi era, which lasted from 1933 until his suicide in 1945. He rose to power as the leader of the Nazi Party, becoming the chancellor of Germany in 1933 and then taking the title of Führer und Reichskanzler in 1934. Germany's invasion of Poland on 1 September 1939 under his leadership marked the outbreak of the Second World War. Throughout the ensuing conflict, Hitler was closely involved in the direction of German military operations as well as the perpetration of the Holocaust, the genocide of about six million Jews and millions of other victims.

Hitler was born in Braunau am Inn in Austria-Hungary and moved to Germany in 1913. He was decorated during his service in the German Army in the First World War, receiving the Iron Cross. In 1919, he joined the German Workers' Party (DAP), the precursor of the Nazi Party, and in 1921, was appointed the leader of the Nazi Party. In 1923, he attempted to seize governmental power in a failed coup in Munich and was sentenced to five years in prison, serving just over a year. While there, he dictated the first volume of his autobiography and political manifesto Mein Kampf (lit. 'My Struggle'). After his early release in 1924, he gained popular support by attacking the Treaty of Versailles as well as promoting pan-Germanism, antisemitism, and anti-communism with charismatic oratory and Nazi propaganda. He frequently denounced communism as being part of an international Jewish conspiracy. By November 1932, the Nazi Party held the most seats in the Reichstag, but not a majority. Former chancellor Franz von Papen and other conservative politicians convinced President Paul von Hindenburg to appoint Hitler as chancellor on 30 January 1933. Shortly thereafter on 23 March, the Reichstag passed the Enabling Act of 1933, which ultimately began the Weimar Republic's transformation into Nazi Germany.

The unequal treaties were a series of agreements made between Asian countries—most notably Qing China, Tokugawa Japan and Joseon Korea—and Western countries—most notably the United Kingdom, France, Germany, Austria-Hungary, Italy, the United States and Russia—during the 19th and early 20th centuries. They were often signed following a military defeat suffered by the Asian party, or amid military threats made by the Western party. The terms specified obligations to be borne almost exclusively by the Asian party and included provisions such as the cession of territory, payment of reparations, opening of treaty ports, relinquishment of the right to control tariffs and imports, and granting of extraterritoriality to foreign citizens.

With the rise of Chinese nationalism and anti-imperialism in the 1920s, both the Kuomintang and the Chinese Communist Party used the concept to characterize the Chinese experience of losing sovereignty between roughly 1840 to 1950. The term "unequal treaty" became associated with the concept of China's "century of humiliation", especially the concessions to foreign powers and the loss of tariff autonomy through treaty ports, and continues to serve as a major impetus for the foreign policy of China today.

Slovakia, officially the Slovak Republic, is a landlocked country in Central Europe. It is bordered by Poland to the north, Ukraine to the east, Hungary to the south, Austria to the west, and the Czech Republic to the northwest. Slovakia's mostly mountainous territory spans about 49,000 km (19,000 sq mi), hosting a population exceeding 5.4 million. The capital and largest city is Bratislava, while the second largest city is Košice.

The Slavs arrived in the territory of the present-day Slovakia in the 5th and 6th centuries. From the late 6th century, parts of modern Slovakia were incorporated into the Avar Khaghanate. In the 7th century, the Slavs played a significant role in the creation of Samo's Empire. When the Avar Khaghanate dissolved in the 9th century, the Slavs established the Principality of Nitra before it was annexed by the Principality of Moravia, which later became Great Moravia. When Great Moravia fell in the 10th century, the territory was integrated into the Principality of Hungary at the end of the 9th century, which later became the Kingdom of Hungary in 1000. In 1241 and 1242, after the Mongol invasion of Europe, much of the territory was destroyed, but was recovered largely thanks to Hungarian king Béla IV. During the 16th and 17th centuries, southern portions of present-day Slovakia were incorporated into provinces of the Ottoman Empire. The Ottoman-controlled areas were ceded to the Habsburgs by the turn of the 18th century. The Hungarian declaration of independence in 1848 was followed in the same year by the Slovak Uprising through the establishment of the Slovak National Council. While the uprising did not achieve its aim, it played an important role in cementing a Slovak national identity. The Hungarian wars of independence eventually resulted in a compromise that established the Austro-Hungarian Empire.

The Kingdom of Yugoslavia was a country in Southeast and Central Europe that existed from 1918 until 1941. From 1918 to 1929, it was officially called the Kingdom of Serbs, Croats, and Slovenes, but the term "Yugoslavia" (lit. 'Land of the South Slavs') has been its colloquial name as early as 1922 due to its origins. The official name of the state was changed to "Kingdom of Yugoslavia" by King Alexander I on 3 October 1929.

The preliminary kingdom was formed in 1918 by the merger of the provisional State of Slovenes, Croats and Serbs (itself formed from territories of the former Austro-Hungarian Empire, encompassing what is now Bosnia and Herzegovina and most of what are now the states of Croatia and Slovenia) and Banat, Bačka and Baranja (that had been part of the Kingdom of Hungary within Austria-Hungary) with the formerly independent Kingdom of Serbia. In the same year, the Kingdom of Montenegro also proclaimed its unification with Serbia, whereas the regions of Kosovo and what is today North Macedonia had become parts of Serbia prior to the unification.