Why did Austria and Prussia go to war in 1866?

1863 - Prussia and Austria had different aims for Germany's future

The Polish revolt:

• 1863 - revolution in Russian Poland 
• Bismarck viewed the situation with concern as he though it might escalate into a general Polish uprising 
• Tsar Alexander II ordered it to be suppressed
• Bismarck took the opportunity to gain Russian friendship by offering military assistance 
• The Tsar rejected the offer but agreed to a convention by which Prussia would hand over any Polish rebels who crossed the border 
• German liberals, who hated autocratic Russia, protested at Bismarck's actions
• France, Britian and Austria also protested 
• Bismarck wanted to improve his diplomatic position so claimed the convention didn't exist 
• This angered the tsar and Prussia was left seemingly friendless
• 1864 - Polish rising was suppressed 
• It was likely that Russia would remain neutral if Prussia went to war with Austria and France because they had been offended by Austria and France 

The problem of Schleswig and Holstein:

• November 1863 - Frederick VII of Denmarck died childless 
• Holstein was a member of the German Confederation; Schleswig was not 
• Christian of Glucksburg was the rightful heir to the throne - but S-H contested his claim as the inheritance through the female line was forbidden 
• Schleswig-Holsteiners put forward the Prince of Augustenberg - but he did not want to be King, however he never formally renounced his rights 
• November 1863:
  • Christian became King
  • Government in Holstein refused to swear allegiance to him
  • Duke of Augustenberg claimed both the duchies as his father had not signed the rights away to them 
  • this was supported by German nationalists 
• King Christian put himself in the wrong by incorporating Schleswig into Denmarck, violating the 1952 Treaty of London
• December 1863 - small German states sent an army into Holstein on behalf of the Duke 
• The Duke became a symbol of German nationalism 
• Bismarck's aims:
  • not influenced by public opinion 
  • annex the two duchies
  • strengthen Prussian power in north Germany 
  • win credit for himself 
  • no wish for the Duke of Augustenberg to control an independent state
  • did not care for Germans in the duchies
• Bismarck first won Austrian help
• Austria was suspicious of German nationalism, but was happy to continue with the traditional policy of co-operating with Prussia
• Bismarck kept his expansionist agenda secret 
• …