Europe 1866: Outbreak of the Austro-Prussian War

After the war with Denmark, Austria and Prussia were left in control of Schleswig-Holstein. However the Prussian Prime Minister Otto von Bismarck really wanted both duchies and connived to provoke a war with Austria. Most of the German states backed Austria, voting for mobilization against Prussia in the German Federal Diet.

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Main Events

9 May 1865 American Civil War ends

American Civil War ends in wikipedia

14 Aug 1865 Gastein Convention

Following disagreements about how to proceed with Schleswig-Holstein—Austria wanted it to become a unified state within the German Confederation whereas Prussia wanted to annex the territory—Austria and Prussia agreed to jointly administer the region as a condominium in December 1864. This uneasy situation lasted until August 1865, when Prussian Minister President Otto von Bismarck and Austrian ambassador Gustav von Blome met at Bad Gastein in Austria to work out a better solution. The resulting Gastein Convention divided up the condominium, giving the administration of Schleswig to Prussia and the administration of Holstein to Austria, and also ceding Lauenburg to Prussia in return for 2.5 million Danish thalers. However, this process of land-swapping offended the other states of the German Confederation and was treated with suspicion by France and Britain. in wikipedia

8 Apr 1866 Prusso-Italian alliance

Starting in July 1865 Prussia began approaching Italy about a possible alliance against Austria, but it was only after Emperor Napoleon III of France assured them that they had his backing that the Italians agreed. As a result Italian representatives Giulio De Barral and Giuseppe Govone met with Prussian Minister-President Otto von Bismarck in Berlin, where, on 8 April 1866, they signed a treaty of alliance. The treaty—which by design only held for three months if Prussia did not declare war on Austria—stipulated that Italy would declare war on Austria after Prussia did so and that neither power would make a separate peace once war had begun, although peace could not be refused if Austria agreed to cede Venetia to Italy and an area equivalent in population to Prussia. in wikipedia

31 May 1866 French withdrawal from Mexico

On 22 January 1866 French Emperor Napoleon III, facing increasing domestic and international pressure to end the French campaign in Mexico, declared his Mexican intervention a success and began preparations for troop withdrawal. In late May and early June, French units were recalled from across Mexico to reassemble in Mexico City and embark from Veracruz. By February 1867 most of the remaining French, Austrian, and Belgian forces had departed for Europe, leaving Emperor Maximilian of Mexico greatly weakened. in wikipedia

9–12 Jun 1866 Prussian invasion of Holstein

In early June 1866 Prussian Minister President Otto von Bismarck declared that Austria’s decisions to bring the Schleswig-Holstein dispute before the German Diet and to convene the Diet of Holstein had violated the Gastein Convention of August 1865. Determined to resolve the crisis by force, Prussia invaded Austrian-administered Holstein from Prussian-administered Schleswig on the 9th and rapidly gained control of the duchy. in wikipedia

14 Jun 1866 German Confederation’s mobilization against Prussia

In response to the Prussian invasion of Austrian-administered Holstein in June 1866, the Diet of the German Confederation voted for partial mobilization against Prussia, starting the Austro-Prussian War. The states supporting Austria in this vote included the four lesser German kingdoms—Bavaria, Hanover, Saxony, and Württemberg—as well as the grand duchies of Baden and Hesse, and the smaller states of southern Germany. The Elecorate of Hesse remained neutral at first, but joined Austria as a matter of principle when Prussia tried to bribe it with land from the Grand Duchy of Hesse the following day. in wikipedia