The Habsburg Dynasty was the ruling house of the Austro-Hungarian Empire. This empire sided with the Central Powers of Germany, Bulgaria, and the Ottoman Empire during World War I. Defeats early in the war caused Austria-Hungary to rely more and more on Germany as an ally. The defeat of the Germany, as well as widespread economic troubles, caused a rapid weakening of the empire. Following the end of the war, the Austro-Hungarian Empire was dissolved, making way for the creation of new countries such as Hungary, Austria, and Czechoslovakia.
The answer would be : Austria and Hungary. The fall of the empire associated with the house of Habsburg after world war I led to the creation of Austria and Hungary. Before the incident that cause world war 2, the House of Habsburg was the most influential House in the Europe Region
