France Declares War on Turkey

Italy had been allied with the German and Austro-Hungarian Empires since 1882 as part of the Triple Alliance.

However, the nation had its own designs on Austrian territory in Trentino, Istria and Dalmatia. Rome had a secret 1902 pact with France, effectively nullifying its alliance. At the start of hostilities, Italy refused to commit troops, arguing that the Triple Alliance was defensive in nature, and that Austria–Hungary was an aggressor. The Austro-Hungarian government began negotiations to secure Italian neutrality, offering the French colony of Tunisia in return. The Allies made a counter-offer in which Italy would receive the Alpine province of South Tyrol and territory on the Dalmatian coast after the defeat of Austria–Hungary. This was fomalised by the Treaty of London. Further encouraged by the Allied invasion of Turkey in April 1915, Italy joined the Entente and declared war on Austria–Hungary on May 23. Fifteen months later Italy declared war on Germany.

World War I (abbreviated as WW-I, WWI, or WW1), also known as the First World War, the Great War, the World War (prior to the outbreak of the Second World War), and the War to End All Wars, was a global military conflict which involved most of the world's great powers, assembled in two opposing alliances: the Allies of World War I centred around the Triple Entente and the Central Powers, centred around the Triple Alliance. More than 70 million military personnel, including 60 million Europeans, were mobilized in one of the largest wars in history. More than 15 million people were killed, making it one of the deadliest conflicts in history.