Erfurt Union

The Erfurt Union (German: Erfurter 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. The union never came into effect, and seriously undermined in the Punctation of Olmütz (November 29, 1850; also called the Humiliation at Olmütz) under pressure from the Austrian Empire.

In the Revolutions of 1848, the Austrian-dominated German Confederation was dissolved, and the Frankfurt Assembly sought to establish new constitutions for the multitude of German states. The effort, however, ended in the Assembly's collapse, after King Frederick William IV refused the German crown. The Prussian government, under the influence of General Joseph Maria von Radowitz, who sought to unite the landed classes against the threat to Junker domination, seized the opportunity to initiate a new German federation under the leadership of the Hohenzollern monarch. At the same time, Frederick William IV acceded to his people's demands for a constitution, also agreeing to become leader of a united Germany.

A year before the convention of the Erfurt Union Parliament, the May 26, 1849 Alliance of the Three Kings was concluded between Prussia, Saxony and Hanover, the latter two of which explicitly made the reservation of departure unless all other principalities with the exception of Austria joined. From this treaty sprung the Prussian policy of fusion, and thence the ambition of the Erfurt Union, which in its constitution abandoned universal and equal franchise in favour of the traditional three-class franchise. The constitution itself, however, was only to come into effect after revision and ratification by an elected Reichstag, as well as approval by the participating governments. 150 former liberal deputies to the German national assembly had acceded to the draft at a meeting in Gotha on June 25, 1849, and by the end of August 1849, almost all (twenty-eight) principalities had recognised the Reich constitution and joined the union, due in varying degrees to Prussian pressure.

...
Wikipedia