Commissioned into service in the Italian Regia Marina (Royal Navy) in 1905, she served in World War I, playing an active role in the Adriatic campaign.

Her coal-fired boilers were converted into oil-fired ones, and her original two short, squat funnels were replaced with three smaller, more streamlined ones, profoundly altering her appearance.

At the time, Espero, under the command of Capitano di corvetta (Corvette Captain) Bellavita, as well as her sister ships Aquilone, Borea, Nembo, and Turbine made up the 5th Destroyer Squadron, based at Taranto.

[5] At 19:00 on 8 June 1916 Espero departed Vlorë (known to the Italians as Valona) in the Principality of Albania with the protected cruiser Libia and the destroyers Impavido, Insidioso, and Pontiere to escort the armed merchant cruiser Principe Umberto and the troopship Romagna, which together had embarked the 2,605 men of the Italian Royal Army′s (Regio Esercito′s) 55th Infantry Regiment for transportation to Italy.

Principe Umberto sank in a few minutes about 15 nautical miles (28 km; 17 mi) southwest of Cape Linguetta with the loss of 1,926 of the 2,821 men on board, the worst naval disaster of World War I in terms of lives lost.

Before Italy entered World War I, it had made a pact with the Allies, the Treaty of London of 1915, in which it was promised all of the Austrian Littoral, but not the city of Fiume (known in Croatian as Rijeka).

At the time, Espero was serving in the Adriatic Sea on escort duty on the shipping route between Šibenik (known to the Italians as Sebenico) and Trieste.