Political map of Europe & the Mediterranean 29 April 1850 (Erfurt Union): The restoration of Austrian power in Hungary (Hungarian Revolution of 1848) and northern Italy (First Italian War of Independence) encouraged Hanover and Saxony to abandon their alliance with Prussia (Alliance of the Three Kings). Undeterred, the Prussians pushed ahead with the creation of the Erfurt Union, successfully drawing most of the smaller German states into a new federation under Prussian leadership.