Treaty of Saint-Germain-en-Laye (1919) in the context of "Trentino-Südtirol"

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.

Trentino-Alto Adige/Südtirol (Italian: Trentino-Alto Adige [trenˈtiːno ˈalto ˈaːdidʒe]; Austrian German: Trentino-Südtirol; Ladin: Trentin-Südtirol), often known in English as Trentino-South Tyrol or by its shorter Italian name Trentino-Alto Adige, is an autonomous region of Italy, located in the northern part of the country. The region has a population of nearly 1.1 million, of whom 62% speak Italian as their mother tongue (in areas where the local languages are transition dialects between Eastern Lombard and Venetian), 30% speak German (around 93% of whom are fluent in the local South Tyrolean dialect of Bavarian), and the remaining are minority speakers of Ladin, Mòcheno or Cimbrian and immigrant communities speaking several foreign languages. Since the 1970s, most legislative and administrative powers have been transferred to the two self-governing provinces that make up the region: the province of Trento, commonly known as Trentino, and the province of Bolzano, commonly known as South Tyrol (Italian: Alto Adige; German: Südtirol). In South Tyrol, German remains the sizeable majority language.

From the 9th century until 1801, the region was part of the Holy Roman Empire. After being part of the short-lived Napoleonic Republic of Italy and Napoleonic Kingdom of Italy, the region was part of the Austrian Empire and its successor Austria-Hungary from 1815 until its 1919 transfer to Italy in the Treaty of Saint-Germain-en-Laye at the end of World War I. Together with the Austrian state of Tyrol, it is part of the Euroregion of Tyrol-South Tyrol-Trentino.

Austrians (German: Österreicher) are the citizens and nationals of Austria. The English term Austrians was applied to the population of Habsburg Austria from the 17th or 18th century. Subsequently, during the 19th century, it referred to the citizens of the Empire of Austria (1804–1867), and from 1867 until 1918 to the citizens of Cisleithania. In the closest sense, the term Austria originally referred to the historical March of Austria, corresponding roughly to the Vienna Basin in what is today Lower Austria.

Historically, Austrians were regarded as Germans and viewed themselves as such. The Austrian lands (including Bohemia) were part of the Holy Roman Empire and the German Confederation until the Austro-Prussian War in 1866 which resulted in Prussia expelling the Austrian Empire from the Confederation. Thus, when Germany was founded as a nation-state in 1871, Austria was not a part of it. In 1867, Austria was reformed into the Austro-Hungarian Empire. After the collapse of the Austro-Hungarian Empire in 1918 at the end of World War I, Austria was reduced to a rump state and adopted and briefly used the name the Republic of German-Austria (German: Republik Deutschösterreich) in an attempt for union with Germany, but was forbidden due to the Treaty of Saint-Germain-en-Laye (1919). The First Austrian Republic was founded in 1919. Nazi Germany annexed Austria with the Anschluss in 1938.

The dissolution of Austria-Hungary was a major political event that occurred as a result of the growth of internal social contradictions and the separation of different parts of Austria-Hungary. The more immediate reasons for the collapse of the state were World War I, the worsening food crisis since late 1917, general starvation in Cisleithania during the winter of 1917–1918, the demands of Austria-Hungary's military alliance with the German Empire and its de facto subservience to the German High Command, and its conclusion of the Bread Peace of 9 February 1918 with Ukraine, resulting in uncontrollable civil unrest and nationalist secessionism. The Austro-Hungarian Empire had additionally been weakened over time by a widening gap between Hungarian and Austrian interests. Furthermore, a history of chronic overcommitment rooted in the 1815 Congress of Vienna in which Metternich pledged Austria to fulfill a role that necessitated unwavering Austrian strength and resulted in overextension. Upon this weakened foundation, additional stressors during World War I catalyzed the collapse of the empire. The 1917 October Revolution and the Wilsonian peace pronouncements from January 1918 onward encouraged socialism on the one hand, and nationalism on the other, or alternatively a combination of both tendencies, among all peoples of the Habsburg monarchy.

The remaining territories inhabited by divided peoples fell into the composition of existing or newly formed states. Legally, the collapse of the empire was formalized in the September 1919 Treaty of Saint-Germain-en-Laye with Austria, which also acted as a peace treaty after the First World War, and in the June 1920 Treaty of Trianon with Hungary. Later, additional territories were ceded to other countries.

Trentino (Lombard, Venetian and Ladin: Trentin, German: Trient), officially the Autonomous Province of Trento (Italian: provincia autonoma di Trento), is an autonomous province of Italy in the country's far north. Trentino and South Tyrol constitute the region of Trentino-Alto Adige/Südtirol, an autonomous region under the constitution. The province is composed of 166 comuni (municipalities). Its capital is the city of Trento (Trent). The province covers an area of more than 6,000 km (2,300 sq mi), with a total population of 541,098 in 2019.

Trentino has a complex history shaped by its position between Italian and Central European cultural spheres. In antiquity, it was inhabited by the Raetian people before being incorporated into the Roman Empire as part of the province of Raetia. During the Middle Ages, Trentino became part of the Prince-Bishopric of Trent within the Holy Roman Empire and later fell under Austrian rule until the end of World War I. Following the war and the Treaty of Saint-Germain-en-Laye (1919), South Tyrol was annexed to the Kingdom of Italy which separated it into two provinces renamed in 1923 as "Trentino" and "Alto Adige". It gained autonomy after World War II under Austrian protection.

The First Austrian Republic (German: Erste Österreichische Republik), officially the Republic of Austria, was created after the signing of the Treaty of Saint-Germain-en-Laye on 10 September 1919—the settlement after the end of World War I which ended the Habsburg rump state of Republic of German-Austria—and ended with the establishment of the authoritarian Federal State of Austria based upon a dictatorship of Engelbert Dollfuss and the Fatherland Front in 1934. The Republic's constitution was enacted on 1 October 1920 and amended on 7 December 1929. The republican period was increasingly marked by violent strife between those with left-wing and right-wing views, leading to the July Revolt of 1927 and the Austrian Civil War of 1934.

Reschen Pass (German: Reschenpass, pronounced [ˈrɛʃn̩ˌpas] ; Italian: Passo di Resia [ˈpasso di ˈrɛːzja]) is a mountain pass across the main chain of the Alps, connecting the Upper Inn Valley in the northwest with the Vinschgau region in the southeast. Since 1919, the border between South Tyrol, Italy and Tyrol, Austria has approximately followed the watershed, the pass summit at a height of 1,504 metres (4,934 ft) being completely on Italian territory.

Carinthia (Slovene: Koroška [kɔˈɾóːʃka] ; German: Kärnten), also Slovene Carinthia or Slovenian Carinthia (Slovenska Koroška), is a traditional region in northern Slovenia. The term refers to the small southeasternmost area of the former Duchy of Carinthia, which after World War I was allocated to the State of Slovenes, Croats and Serbs according to the 1919 Treaty of Saint-Germain. It has no distinct centre, but a local centre in each of the three central river valleys among the heavily forested mountains. Towns that make urban centers include Ravne, Prevalje, Mežica and Dravograd.

Since the entry of Slovenia into the European Union in May 2004, much effort has been made to re-integrate Carinthia as a cultural, tourism, and economic unit. The historical region has no official status within Slovenia and does not territorially correspond to today's Carinthia Statistical Region, but popular identification with Carinthia as an informal province remains common.

The U.S.–Austrian Peace Treaty is a peace treaty between the United States and Austria, signed in Vienna on August 24, 1921, in the aftermath of the First World War. This separate peace treaty was required because the United States Senate refused to advise and consent to the ratification of the multilateral Treaty of Saint-Germain-en-Laye of 1919.

Ratifications were exchanged in Vienna on November 8, 1921, and the treaty became effective on the same day. The treaty was registered in League of Nations Treaty Series on November 22, 1921.