What happened to Austria-Hungary in 1918? Name the newly independent nations that were created in Europe.

In 1918, Austria-Hungary underwent significant changes as a result of World War I and the dissolution of the Habsburg monarchy. The empire was a complex multiethnic state composed of various regions with diverse populations.

At the end of World War I, Austria-Hungary disintegrated, and several newly independent nations emerged in Europe. The Treaty of Trianon in 1920 and subsequent treaties redefined the borders and created new countries. Here are the main newly independent nations that emerged:

1. Austria: The Republic of Austria was established, containing most of the territories inhabited by the German-speaking population of Austria-Hungary.

2. Hungary: The Kingdom of Hungary emerged as a separate country, although its territory was significantly reduced compared to the former Austro-Hungarian borders.

3. Czechoslovakia: The creation of Czechoslovakia resulted from the joining of the Czech lands (Bohemia, Moravia, and parts of Silesia) with Slovakia. It became a multiethnic state with a large Czech and Slovak population.

4. Yugoslavia: The Kingdom of Serbs, Croats, and Slovenes was established, later renamed Yugoslavia. It included territories that had previously belonged to Austria-Hungary, including Slovenia, Croatia, Bosnia and Herzegovina, Montenegro, Serbia, and parts of Macedonia.

5. Poland: The Second Polish Republic was established, which gained independence after more than a century of partitions. It included territories that had been part of Germany, Russia, and Austria-Hungary.

These were the major newly independent nations created in Europe after the dissolution of Austria-Hungary. It's important to note that the political landscape of Europe was further shaped by subsequent territorial adjustments and geopolitical developments during and after World War I.