When looking to add to the cruiser squadrons, the first issue for Tyrrhenia, was to figure out what it wanted to build. The Syracuse class large cruisers were under construction, but they were patrol cruisers, what was needed was some light cruisers for fleet escort duties, like the British and Germans had used their light cruisers for. The Tyrrhenian Navy would need assistance again with the design work as it was 10 years since the Emperor class had been built and they had been built on a British design. The United States, Russia, Italy, France, had also not built any small cruisers for 10 years or so. That left the British and Germans. Not unsurprisingly the Germans were discounted as Tyrrhenia was at war with them, which left the British. Naval Attaches in Britain asked for and were shown designs for the various 'C' class projects and were also appraised of the early design work for the larger 'D' class designs. The Tyrrhenian Navy liked the look of the 'D' class for what they wanted and asked for the basic design plans and these were provided to Britain's Ally.
This cruiser class was always going to be armed with the twin 5.5" gun turret design that was supposed to originally be fitted on the Sardinia Class battlecruisers and was used on the subsequent Crete and Majorca classes as secondary armaments. With the 'D' class design there could be four of the twin turrets fitted, while the 'C' class design would have only taken three. The British took note of the final resulting design and followed it with their own 'G' class a few years later. Besides being turret armed, one of the other significant profile changes was the removal of the large spotting top and high wireless masts which were not required by a ship operating in the Mediterranean.
While the three ships were essentially complete and in service by 1920-21, it was not until 1930 that the final bits of the armament and the gunnery control units were fitted. Very little was done to the ships prior to the beginning of the war. The capital ships and big cruisers used up all of the available funds for rebuilds. All that was done was the fitting of 3 twin 25mm cannons One plan during the 1930's was to fit the ships with aircraft handling facilities but the compromises and reduction of armament to be able to fit a catapult, crane and plane, was just too much and the idea was shelved.
The slower speed of these three ships meant they spent a lot of their time acting as leaders to the World War One era destroyers.
Gozo was lost along with two destroyers defending against the British Force K ships (2 CL's and 4 DD's) covering a convoy headed for North Africa. A torpedo hit then multiple 4.5" and 6" shell hits, and the Gozo sank.
Palma was in port at Palma when the fleet was attacked by the two carriers aircraft from Force H. Hit by three 500lb bombs, one detonated the aft 5.5" magazine and blew the rear 100 odd feet off the ship, which then drifted ashore. Deemed a constructive loss, the ship was stripped of useful equipment and abandoned. The hulk eventually being refloated, towed away and scrapped.
The Nicosia survived the war, being ceded to the USA which expended the ship as part of the Bikini Atoll atomic bomb tests. The ship capsized and sank in the lagoon.