The Battle of Langensalza is fought on June 27, 1866 near Bad Langensalza in what is now modern Germany, between the Kingdom of Hanover (Hanoverians) and the Prussians.

The Hanoverians win the battle but are then surrounded by a larger and reinforced Prussian army, and, unable to link up with their Bavarian allies to the south, they surrender.

This marks the demise of the Hanoverian Army and the annexation of Hanover into the burgeoning kingdom of Prussia as it systematically unifies Germany into the modern nation state.