It comprised the Magyar-dominated "lands of the Crown of Saint Stephen", the core of which was the Kingdom of Hungary and was sometimes referred to as Transleithania,[note 1] and the German-dominated remainder of the empire, informally called "Austria" but semi-officially given the name Cisleithania.

[5][6] The dual monarchy, or Austria-Hungary as it came to be known, was effectively two states with the Habsburg monarch as Emperor of Austria in Cisleithania and King of Hungary in Transleithania.

By May 1918, the empire was facing increasing military failure and defeat, as well as domestic unrest caused by food and fuel shortages.

Additionally, the demands of the empire's nationalities were becoming increasingly radicalised, encouraged by the American president Woodrow Wilson's commitment to self-determination in his Fourteen Points published in January 1918.

In October, the independence of Czechoslovakia and the State of Slovenes, Croats and Serbs (the latter unified with Serbia that December to form the Kingdom of Serbs, Croats and Slovenes, later called Yugoslavia), Hungary withdrew from the dual monarchy and the Austro-Hungarian army surrendered to Italy at Vittorio Veneto.

[note 3][14][12] On 21 October 1918, the deputies representing German-speaking areas in the Abgeordnetenhaus, the lower chamber of the Reichsrat, the imperial Parliament of Cisleithania, declared that they were the new Provisional National Assembly for German-Austria.

[15] With the impending collapse of the empire becoming apparent earlier in the month, the three main political groupings representing German-speakers in the lower chamber began negotiations on the way forward.

[17] Calling themselves "the Germans of the Alps and Sudetens",[10] all 208 deputies met on 21 October, and unanimously voted that they now constituted the "Provisional National Assembly" for German-Austria.

[18] They declared that: the German people in Austria are resolved to determine their own future political organization to form an independent German-Austrian state, and to regulate their relations with other nations through free agreements with them.

He deliberately avoided using the term "abdication", as he wanted to retain his freedom of action in the event that his Austrian subjects recalled him.

The next day, 12 November, the National Assembly officially declared German-Austria a republic and named Social Democrat Karl Renner as provisional chancellor.

[21] The latter provision reflected the deputies' view that felt that Austria would lose so much territory in any peace settlement that it would no longer be economically and politically viable as a separate state, and the only course was union with Germany.

As the Empire collapsed and a ceasefire was announced, the Provisional Assembly sought to forestall socialist revolution by organizing a coalition government led by the minority Social Democrats.

After submitting a formal note of protest to the Allies against blocking German-Austrian union, on 10 September 1919 Renner signed the Treaty of Saint Germain and it was ratified by the Constituent National Assembly on 17 October.

[25] On 22 November, the national assembly officially claimed sovereignty over all the majority-German territory of the former Habsburg realm: a total area of 118,311 km2 (45,680 sq mi) with 10.4 million inhabitants.

This included nearly all the territory of present-day Austria, plus South Tyrol and the town of Tarvisio, both now in Italy; southern Carinthia and southern Styria, now in Slovenia; the recently proclaimed provinces of Sudetenland and German Bohemia (which later became parts of Nazi Sudetenland), now in the Czech Republic; and East Silesia (now divided between Poland and Czech Republic).

German-Austria was largely powerless to prevent the forces of Italy, Czechoslovakia, and the Kingdom of Serbs, Croats, and Slovenes from seizing some of its territory.

The Czechs insisted on the historic borders of the Lands of the Bohemian Crown; thus, three million Germans became Czechoslovak citizens, an indirect precipitant of the Sudetenland crisis 20 years later.

On the other hand, ethnic Germans in the western part of the Kingdom of Hungary that formed a majority in the area known as German West Hungary and agitated to join to Austria were successful and the area became the state of Burgenland, with the notable exception of the region around the city of Ödenburg (Sopron) which was also intended to be the state capital, but due to a very contentious[by whom?]