Dreikönigsbündnis
The Erfurt Union () was a short-lived union of German states under a federation, proposed by the Kingdom of Prussia at Erfurt, for which the Erfurt Union Parliament ("Erfurter Unionsparlament"), lasting from March 20 to April 29, 1850, was opened at the former Augustinian monastery in Erfurt. The union never came into effect, and was seriously undermined in the Punctation of Olmütz (November 29, 1850; also called the Humiliation at Olmütz) under immense pressure from the Austrian Empire.