What was the union with Austria?

* Anschlus:

* Union between the German Empire and the Republic of Austria during the First World War

* Union of Nazi Germany with Austria in the 1938 Annexation of Austria

* Proposed union of Austria with the German Democratic Republic and Third German Reich during the Cold War as a Neutral Germany project

* Union between the Kingdom of Hungary and the Kingdom of Croatia-Slavonia during the Austro-Hungarian Compromise

* Proposed United States of Greater Austria