June 14, 1866

Austro-Prussian War

German Diet orders federal mobilization against Prussia

The war opened with a committee vote of nine to five, taken under a system of shared curial ballots — not with declarations of war by Austria and its allies.

Frankfurt, 14 June

Meeting at Frankfurt on 14 June 1866, the Federal Diet of the German Confederation approved Austria's motion to mobilise the non-Prussian federal army corps against Prussia. Aloys Freiherr von Kübeck had introduced it three days earlier.

Austria, Bavaria, Saxony, Hanover, Württemberg, the two Hessian votes and supporting curiae carried the motion nine to five, with one abstention. It named seven federal corps and required them to be war-ready within fourteen days and able to march within twenty-four hours of an order.

Prussia walked out

Prussia rejected the resolution as unconstitutional. Its representative Karl von Savigny announced Prussia's withdrawal and treated the German Confederation as dissolved — the declaration came from Savigny in the chamber, not from Bismarck.

Behind the vote lay Schleswig-Holstein: Prussia had moved troops into Austrian-administered Holstein after Austria referred the dispute to the Diet and unilaterally convened the Holstein estates.

A federal execution, not a declaration of war

What the Diet ordered was a federal mobilisation framed legally as action by the Confederation, not separate declarations of war by Austria and most medium-sized German states. "Most German states" also misreads a body that voted by weighted and shared curiae rather than one state, one vote.

On 15 June Prussia issued ultimatums to Hanover, Saxony and Electoral Hesse; after they were refused, Prussian forces entered the three states on 16 June.

The 14 June vote itself is securely dated. What varies is which day gets called the start of the war: legal histories begin with the federal execution, some military chronologies with the ultimatums or the entries.

Sources

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What the sources leave uncertain

The June 14 vote is securely dated. What varies is the labeled beginning of the war: legal histories begin with the June 14 federal execution, while some military chronologies prefer the June 15 ultimatums or June 16 invasions.
Published vote totals sometimes differ because several smaller states shared curial votes and sources handle abstentions or Prussia's participation differently. The detailed German Federal Agency for Civic Education account gives nine for, five against, and one abstention.