Known in Italy as Giornata del Decorato, May 24 is the date that Italy entered the First World War against Austria and Germany in 1915. On this day, Italy honors its veterans and remembers its role in the war.
At the beginning of World War I, Italy had remained neutral, claiming that the Triple Alliance had only defensive purposes and that the war was started by the Austro-Hungarian Empire. However, both the central empires and the Triple Entente tried to attract Italy to their sides, and, in April 1915, the Italian government signed the London Pact, agreeing to declare war on the Austro-Hungarian Empire. The London Pact—Patto di Londra in Italian—or, more correctly, the Treaty of London was a secret pact signed in London on April 26, 1915, by the Triple Entente, consisting of the United Kingdom, France, Russia and the Kingdom of Italy. Its intent was to gain the alliance of Italy against its former allies, including Germany.
According to the pact, Italy was to leave the Triple Alliance and join the Triple Entente. Italy also was to declare war against Germany and Austria-Hungary within a month—which did happen against Austria-Hungary, officially on May 24, but not until 1916 against Germany.
Assuming victory against Germany and its allies, the Triple Entente promised Italy territorial gains at the end of the war. In particular, it was an opportunity for Italy to complete the process of Italian national unity and rid the Trentino-Alto Adige and Friuli-Venezia Giulia regions of Austrian rule.
In October 1917, the Austrians, having received German reinforcements, broke the Italian lines at Caporetto. The Italians, helped by their allies, stopped their advance on the river Piave, not far from Venice. A song, “La Leggenda del Piave” (“The Legend of the Piave”), remembers this crucial turning point in the war and remains a key part of annual commemoration.
WWI dragged on for another year of trench warfare. After a successful Italian offensive in the autumn of 1918, the exhausted Austro-Hungarian Empire surrendered to the Allies on Nov. 4, 1918, soon followed by the German Empire.