Treaty of Versailles
In the separate Treaty of Saint-Germain-en-Laye the same year, Austria-Hungary was split into many countries. One was Austria, which was meant to be the homeland of the Austrians, who spoke German and had ruled Austria-Hungary. Its capital was Vienna. One of the problems of the Treaty of Versailles was that most Austrians like Adolf Hitler thought that Austria should become part of Germany. That later led to the German unification of Austria.