This is Why & How Bismarck provoked Austria into war in 1866

The most notable accomplishment of Otto von Bismarck is without a doubt the unification of Germany. But when we look at unified Germany we see that Prussia and not Austria, that until 1806 had provided the emperor of the Holy Roman Empire, provided the german emperor.

But why wasn`t Austria a part of unified Germany although it has had a significant role within the Holy Roman Empire, which was made up of many of the territories that would later form Germany?

The reason why Austria was not a part of unified Germany after the war of 1870/71 can be found in the Austro-Prussian war of 1866.

Bismarcks’ goal was to intensify Prussian influence over the German states by pushing Prussias main rival Austria out of the German Confederation. After provoking Austria with the annexation of territories that were ruled by Prussia and Austria, Prussia went to war with Austria in 1866. The Prussian victory led to the North German Confederation and the exclusion of Austria.

Let`s take a closer look!

Why did Bismarck attack Austria in 1866?

To get a better idea of why Bismarck was so keen on keeping Austria out of german politics we have to take a brief look into the relationship between Prussia and Austria prior to 1866.

Austro-Prussian relationships before 1866

Both Prussia and Austria had been dominant powers during the time of the Holy Roman Empire. More on how the Holy Roman Empire got its name here. And while both nations had clashed during the 18th century, for example in the Seven Years War, both Prussia and Austria had combined their forces to fight and defeat the army of Napoleon Bonaparte in 1815.

But these Napoleonic Wars had changed Europe forever. While since the late middle ages the Holy Roman Empire was the main force on the European continent, that changed in 1806.

On August 6 1806 the Holy Roman Empire was dissolved when the last emperor Francis II, an Austrian, was forced to abdicate after Napoleon had won the battle of Austerlitz. Napoleon transformed large parts of the Holy Roman Empire into the Confederation of the Rhine which was a French satellite state.

The last Holy Roman Emperor Francis and his house of Habsburg would continue to rule as Emperors of Austria and King of Hungary. It wasn`t until the defeat in World War I in 1918 that the monarchy and the dynasty of House Habsburg ended in Austria and Hungary.

After Napoleon Bonaparte had finally been defeated in 1815 Europe had to be reorganized.

Why did Bismarck provoke Austria into the war?

The confederation of the Rhine that was dependent on France was reorganized into the German Confederation without any ties to France.

Within the German Confederation that was founded in 1815, Prussia and Austria were the main rivals for the dominant position. Bismarck knew that to achieve his goal of uniting Germany under Prussian dominance Austria couldn`t be a part of Germany or interfere in the politics of the German states.

Here you can find my article with more information on the member states of the German Confederation.

The rivalry between Prussia and Austria until 1866

That rivalry between Prussia and Austria simmered for quite some time. During the German Revolutions of 1848 and 1849, both states were able to forget their differences for some time but as soon as the danger was over their rivalry intensified.

That intensification can be attributed to Otto von Bismarck. In 1851 Otto von Bismarck was appointed as Prussian prime minister by king Wilhelm I. of Prussia. More on why Bismarck was appointed in my article here.

By the way, Wilhelm I. of Prussia would become the first German emperor and was the Grandfather of emperor Wilhelm II who would rule the German Empire during the first World War.

Bismarck was mainly appointed to drive back the liberal influence within the Landtag of Prussia (the parliament).

The liberals had a majority within the Prussian parliament and were blocking a bill that would allow the Prussian king to increase the size of his army. By the way, it was during that conflict that Bismarck held his famous Blood and Iron speech and became known as the Iron Chancellor.

Please feel free to check out my article here for more information on the Blood and Iron Speech.

The bill was passed and the Prussian military increased its strength. And that strength was first tested in the Second Schleswig War of 1864 (also known as the Prussio-Danish war).

The Second Schleswig War – Austria & Prussia temporarily overcome their rivalry

The Second Schleswig war began on February 1st, 1864 when Austrian and Prussian troops crossed the border to Schleswig.

Thanks to Bismarck’s smart diplomacy the Austrian Empire and Prussia had attacked Denmark together. And after their victory in October of 1864 Austria and Prussia decided to rule the newly conquered former danish duchies of Schleswig, Holstein, and Saxe-Lauenburg together.

The integration of the former danish dutchies into the German Confederation increased Bismarck’s reputation among the German public while Austria was seen as the diplomatic loser.

And that was important for Bismarcks’ next step.

How did Bismarck provoke Austria into the war of 1866?

Otto von Bismarck had the goal to integrate the former danish territories into Prussia. The problem was that Austria, with which Prussia was ruling these dutchies together, opposed that.

And with regards to Bismarcks’ second goal, unifying Germany under Prussian leadership, more on that here, it was obvious that Austria and Prussia would clash.

Bismarck’s goal in the war against Austria

Bismarck’s goal during the following war with Austria was to increase Prussia’s dominance in northern Germany but also to push the Austrian influence out of German politics.

A reason to provoke Austria into war

So tensions rose between Austria and Prussia and Bismarck started looking for a reason that would justify a war against Austria. Additionally, Bismarck also started looking for alliances and insured himself that France would not help Austria in the case of war.

In preparation for war with Austria Bismarck made an alliance with Italy on April 8th, 1886 stating that Italy would join the war if Prussia and Austria would go to war within 3 months.

I would say that is a pretty obvious sign that Bismarck was just looking for a reason he could use to provoke a war.

And he saw an opportunity to pursue his goal by interfering in the domestic politics of Holstein which he hoped would provoke Austria into war.

After Bismarck had interfered in Holsteins’ domestic Politics Austria hoped on using the German diet to convey in the Holstein dispute. But the situation was already negatively charged since Austria had already reinforced their troops on the Austro-Prussian border in March of 1866. Prussia had willingly accepted that justification and had mobilized 5 of its divisions on March 28th, 1866.

When Austria brought the dispute in front of the german diet on June 1st, 1866 it was already too late.

Bismarck argued that by bringing the dispute in front of the german diet the agreement between Prussia and Austria to govern Schleswig Holstein together was breached.

Eight days later, on June 9th, Prussia invaded Holstein.

And when the german diet answered the Prussian invasion of Holstein on June 14th, 1866 by partially mobilizing the army of the German Confederation (obviously without the Prussian contingents) Bismarck declared that the German Confederation had ended.

Simultaneously Bismarck also showed his willingness to form a new confederation with those german states that were willing to accept the Prussian terms, mainly the exclusion of Austria.

There was just one problem. The German Confederation argued that according to article 1 it could not be dissolved.

How did Bismarck attack Austria in 1866?

On June 16th, 1866 Prussia attacked Austria and Bismarck had reached his first goal. Like he had stated in his Blood and Iron speech: The speeches and parliamentary decisions would not decide politics, Blood and Iron would.

What followed was the war of 1866 between Austria and its 13 allies in southern Germany (Saxony, Hannover, the two hessian states, Bavaria, Baden, and Würtemberg) and Prussia and its allies in northern Germany.

Prussian advantages in the Austro-Prussian War

A major part of Prussia’s success can be attributed to the chief of staff of the Prussian Army Helmut von Moltke who was probably the biggest tactical genius since Napoleon Bonaparte.

Another reason for Prussia’s superiority was its rifles.

While Austria used old-fashioned muzzleloading Lorenz rifles that could only be loaded while standing and that could only fire one round per minute. The Prussian Dreyse needle gun was a bolt-action rifle and could not only be loaded while lying or kneeling in cover but could also fire up to 5 rounds per minute.

By the way, the Lorenz Rifle was also the third most used rifle during the American Civil War. The Confederate States alone purchased more than 100.000 pieces. More on the Civil war and why the South seceded immediately after the election of 1860 in my article here.

Because of that superior firepower and Bismarcks’ superior diplomacy, the war was over within 7 weeks. One reason for that kind of short war was that the other European powers did not interfere.

The Russian tsar Alexander II, a nephew of the Prussian king Wilhelm I for example only asked his uncle to not march into Vienna and to treat the Austrian emperor Franz Joseph I like one monarch would treat another monarch.

The main events of the Austro-Prussian war of 1866

  • June 16th, 1866: Prussian troops march into Hannover, Hesse, and Saxony
  • June 20th, 1866: Saxony is occupied by Prussian troops
  • June 29th, 1866: Hannovian troops capitulate at Langensalza
  • July 3rd, 1866: Prussian victory at Königgrätz
  • August 23rd, 1866: Peace of Prague

The aftermath of the Austro-Prussian war

After the Austro-Prussian War was over Bismarck could barely convince the Prussian king from marching into Vienna.

While Bismarck wanted to push Austria out of german politics he still wanted to keep Austria as a potential future ally.

In the aftermath of the war, Prussia annexed 4 of its former enemies and founded the North German Confederation that included all german states north of the river Main. The German states south of the Main were free to form a South German Confederation but that confederation never made it past early plans.

So while the transition from the German Confederation to the North German Confederation went pretty smooth there was another problem.

Right after the battle of Königgrätz on July 3rd, 1866 the French emperor Napoleon III, a nephew of Napoleon Bonaparte, forced itself into the position as an intermediary between Austria and Prussia.

While Austria immediately accepted him as an intermediary Prussia only accepted Napoleon III because it was in no position to wage a war against Austria and France.

Otto von Bismarck was definitely not a fan of that and he even swore that the French emperor would regret that. But Bismarck provoking France into war and Napoleon III regretting his interference of 1866 is a story for another time, more on that here.

So after the war of 1866, Prussia had managed to push the Austrian influence out of the German states and had established the North German Confederation. The next step on the way to the unification of Germany was to bring the german states to the South, for example, Bavaria under its fairy tale king Ludwig II, into a confederation under Prussian control.

Once again it would take Blood and Iron to archive Bismarck’s goal of a unified Germany.

But that is a story for another time. If you are interested in why Otto von Bismarck wanted to unify Germany in the first place you might want to check out my article here.

Take care of yourself because you deserve it. You really do.

Until next time

Yours truly

Luke Reitzer


F. Herre: Bismarck. Der preußische Deutsche (Köln 1991).

C. Graf von Krockow: Bismarck (Stuttgart 1997).