The Battle of Solferino on 24 June 1859 resulted in the victory of the allied French army under Napoleon III and the Piedmont-Sardinian army under Victor Emmanuel II against the Austrian army under Emperor Franz Joseph I. It was the last major battle in world history where all the armies were under the personal command of their monarchs. Perhaps 300,000 soldiers fought in the important battle, the largest since the Battle of Leipzig in 1813. There were about 130,000 Austrian troops and a combined total of 140,000 French and allied Piedmontese troops. After the battle, the Austrian emperor refrained from further direct command of the army.

The Kingdom of Sardinia is a term used to denote the Savoyard state from 1720 until 1861, which united the island of Sardinia with the mainland possessions of the House of Savoy. Before 1847, only the island of Sardinia proper was part of the Kingdom of Sardinia, while the other mainland possessions were held by the Savoys in their own right, hence forming a composite monarchy and a personal union which was formally referred to as the "States of His Majesty the King of Sardinia". This situation was changed by the Perfect Fusion act of 1847, which created a unitary kingdom. Due to the fact that Piedmont was the seat of power and prominent part of the entity, the state is also referred to as Sardinia-Piedmont or Piedmont-Sardinia and sometimes erroneously as the Kingdom of Piedmont.