From the 1880s to 1910s, the Italian Regia Marina (Royal Navy) built or purchased twenty protected cruisers; the earliest vessels were either built or designed in Britain, though later vessels were constructed in Italy, to Italian designs. Several of these cruisers were ground-breaking warships: Dogali was the first major warship equipped with triple-expansion engines and Piemonte was the first warship armed entirely with quick-firing guns. The first two designs, Giovanni Bausan and the Etna class, were armed with large-caliber guns and marked a brief experimentation with the Jeune École in the 1880s, which represented a shift away from expensive battleships in favor of cheaper vessels that could theoretically destroy battleships easily. Italian naval strategists quickly discarded the concept and returned to more traditional strategies centered on a fleet of battleships. As a result, later cruisers returned to medium-caliber batteries.
The first several designs were intended to fill a variety of roles, including fleet scouts and colonial cruisers, but beginning with Calabria, which was solely intended for colonial duties, the Regia Marina began to build more specialized vessels. Quarto, Nino Bixio, and Marsala were designed as fast scouts for the main fleet, and the last design, the Campania class, were slower vessels for use in the colonies. One vessel, Libia, was an exception to Italian design preferences. The ship had been ordered by the Ottoman Navy, but the Ottomans failed to pay for the ship, so she remained incomplete until the Italo-Turkish War in 1911, when she was seized by Italy and completed for the Regia Marina.
Italian protected cruisers served in many roles across the globe. Many were deployed to Italy's colonies in Africa, or to foreign stations in the Americas and Asia to show the flag. They were also assigned to the main fleet in the Mediterranean, where they served as scouts. As the vessels aged, many were converted for secondary duties, becoming training ships, depot ships, and headquarters ships. Many of the early vessels saw action during the Italo-Turkish War, bombarding Ottoman positions in North Africa and the Arabian Peninsula and blockading ports in the Red Sea. During World War I, most of the vessels saw little action, owing to the cautious strategy adopted by both Italy and Austria-Hungary, but Quarto battled an Austro-Hungarian cruiser in 1915 and Marsala took part in the Battle of the Strait of Otranto in May 1917. After the war, most of the remaining vessels were scrapped or reduced to secondary roles, having been supplanted by ex-German and Austro-Hungarian vessels taken as war prizes and newer light cruisers built in the 1920s.
| Armament | The number and type of the primary armament |
|---|---|
| Armor | The thickness of the deck armor |
| Displacement | Ship displacement at full combat load |
| Propulsion | Number of shafts, type of propulsion system, and top speed/horsepower generated |
| Service | The dates work began and finished on the ship and its ultimate fate |
| Laid down | The date the keel began to be assembled |
| Commissioned | The date the ship was commissioned |