The Triple Alliance between the German Empire, Austria-Hungary and the Kingdom of Italy is formed.

The Triple Alliance was a defensive military alliance between Germany, Austria-Hungary, and Italy. It was formed on 20 May 1882 and renewed periodically until it expired in 1915 during World War I. Germany and Austria-Hungary had been closely allied since 1879. Italy was looking for support against France shortly after it lost North African ambitions to the French. Each member promised mutual support in the event of an attack by any other great power. The treaty provided that Germany and Austria-Hungary were to assist Italy if it was attacked by France without provocation. In turn, Italy would assist Germany if attacked by France without provocation. In the event of a war between Austria-Hungary and Russia, Italy promised to remain neutral. After the Austro-Hungarian empire and Germany declared war without first being attacked by other nations, Italy did not take part in World War I on the side of the Central Powers and later joined on the side of the Allied Powers.

Austria-Hungary, also referred to as the Austro-Hungarian Empire, the Dual Monarchy or the Habsburg Monarchy, was a multi-national constitutional monarchy in Central Europe between 1867 and 1918. A military and diplomatic alliance, it consisted of two sovereign states with a single monarch who was titled both the Emperor of Austria and the King of Hungary. Austria-Hungary constituted the last phase in the constitutional evolution of the Habsburg monarchy: it was formed with the Austro-Hungarian Compromise of 1867 in the aftermath of the Austro-Prussian War, following wars of independence by Hungary in opposition to Habsburg rule. It was dissolved shortly after Hungary terminated the union with Austria in 1918 at the end of World War I.

The Kingdom of Italy was a unitary state that existed from 17 March 1861, when Victor Emmanuel II of Sardinia was proclaimed King of Italy, until 10 June 1946, when the monarchy was abolished, following civil discontent that led to an institutional referendum on 2 June 1946. This resulted in a modern Italian Republic. The kingdom was established through the unification of several states over a decades-long process, called the Risorgimento. That process was influenced by the Savoy-led Kingdom of Sardinia, which was one of Italy's legal predecessor states.