The idea of aircraft carriers was always present for the Italian Navy, ever since the ship type existed. As early as the end of WW1 the idea of converting the incomplete Francesco Caracciolo class battleships to carriers was pitched, but never gained serious traction due to financial concerns. The seaplane tender Giuseppe Miraglia was commissioned into the Navy into the 1920s, but never followed up by larger purpose built aviation vessels. It was only during WW2 and the embarassing defeats at Taranto and Matapan that the need for a carrier in the Italian Navy become urgent and well understood.
Commissioned into civilian service as the liner SS Roma in 1926, Aquila was requisition for conversion in 1940 shortly after the Italian declaration of war. The conversion was to be modest, with a flush deck, no island, and a modest aircraft capacity. After the raid on Taranto however, the conversion rapidly evolved into a more ambitious plan for a fleet carrier, with a full island superstructure, large hangar, and over 50 aircraft in the planned air group. Work however was slow and objected on a number of grounds, namely the extreme technical and operational challenges of getting a carrier into service under the duress of wartime, and a lack of any carrier based planes to fly from it.
This all changed when the disastrous battle of Cape Matapan, in early 1941, cost the Italian Navy three of her four best cruisers. The lack of air cover was decisive to this, and the plan to convert Aquila finally went ahead at full speed. Still, there were a number of hurdles to overcome. The arresting gear was a chronic problem, and it was only with German assistance that landings were deemed to be alarmingly hazardous, rather than suicidal. Catapults also had to be outsourced, a pair being imported from the cancelled sister ship of Germany's carrier Graf Zeppelin. The machinery was also replaced so the ship could steam at 30 knots, keeping pace with the fast battleships and cruisers.
All said and done, Aquila was just over 80% complete when the armistice was signed in September of 1943. Unable to leave her berth in Genoa under her own power, she was scuttled to prevent her use by the German forces occupying the city. She remained there until she was broken up after the war, thus ending the story of Italy's only serious attempt at an aircraft carrier in WW2.