The four large light cruisers of the Calloid-class were Thiaria's final cruiser project of the first world war. Two of them - Calloid and Diograis - were completed in time for the first world war and had to be surrendered to the Entente powers in 1919. The other two, LT Cathgangaid (Warspite) and LT Mioscais (Defiance) were still fitting out in 1919. With Brazil and Chile politically firmly in Britain's pocket at that time, the Americans deliberately refrained from totally disarming the Thiarians for possible use in a future proxy war for influence in South America. Cathgangaid and Mioscais were not mentioned in the armistice nor the Peace Treaty of Norfolk, and remained in Thiaria. Due to the strain placed on Thiaria's treasury by reparation payments to Brazil, completion of the two cruisers was considerably delayed; both were towed to naval yards (Cathgangaid to Abernenui, Mioscais to Nuatearman) for completion. The time was used for a thorough redesign, adding some length aft and replacing the original direct-drive turbines with geared ones. Speed remained the same at 28 knots at 50.000 hp, but range increased by half to 8.000 miles at 15 knots and machinery weight was much reduced. The saved weight was used to increase armament to twelve 140mm/55 guns in four twin gunhouses superimposed fore and aft and four single mounts, two on either beam, placing these ships among the strongest light cruisers of the era. Five old-fashioned 75mm singles were installed as heavy flak; light flak was not included in the revised 1921 design. The torpedo battery increased from eight to twelve 559mm tubes in four triple sets. Some changes in protection were worked in (the belt was thinned to 60mm, decks remained at 30mm, but the magazines received extra box protection), and standard displacement increased to 7.050 tons at considerably increased draught. As the peace treaty literally only forbid to begin new construction of cruisers exceeding 6.000 tons, the completion of these 1916 vintage hulls was technically legal. They were completed late in 1924 and in mid-1925, respectively, When they entered service, they looked like this:
During the peacetime routine of the next years, they proved reliable and economic steamers with good seaworthiness and accomodation. The pretty useless 75mm flaks were replaced with semi-automatic 37mm twins in 1930, but otherwise, few changes were made. By the early thirties, their speed of only 28 knots was seen as a liability - during their construction, there had indeed been demands from the naval staff to cut armament to eight 140mm guns, reduce displacement to 6.000 tons and increase horsepower by half for 32 knots speed, but these were rejected in order to give the numerically castrated navy at least a few ships with superior firepower, especially compared with the four E-class derivatives which re-equipped Brazil's battered cruiser fleet after the war. But as Thiaria gradually regained her numerical edge over the Brazilians in the 1930s and cruisers worldwide became larger and more powerful, the idea to compromise on speed so badly to gain some firepower became invalid, and both ships were taken in hand in 1934 and 1935, respectively, for a thorough reconstruction. Four of the 140mm guns were landed and replaced with eight 100mm flaks, and sixteen 13mm HMGs were installed. The number of torpedo tubes was cut from twelve to eight in two quad sets. A catapult was installed, and two scoutplanes could be shipped, but no shelter was provided. Displacement was reduced to 6.480ts. Their machinery was replaced with a 72.000 hp plant giving them 31 knots speed at the same range as before. The new boilers came with re-arranged funnels, giving the ships a less ponderous appearance. In the final years before the war, they looked like this:
When Thiaria entered the war, both cruisers were assigned to the covering group of the battleship squadron. They engaged a powerful Royal Navy task force consisting of four battleships, three fleet aircraft carriers and nine cruisers in the battle of Portiasc, where Cathgangaid was damaged by gunfire of the heavy cruiser HMS Lancaster. Mioscais escaped unharmed; the Thiarian battleship Tuama and the heavy cruisers Craigmiadh and Tranacorr were lost. A few days after, on February 3rd, 1940, Mioscais was bombed by FAA Skuas and suffered three 113kg bomb hits, the worst of them being a near-miss forward which structurally weakened the bow, caused 750 tons of flooding and cut speed to 15 knots. Some hours later, the British light cruiser HMS Phaeton steamed up and finished Mioscais with gunfire and three torpedoes. Cathgangaid needed repairs, but did not enjoy high priority; she needed till November 1940 to rejoin the fleet. During the operations against New Portugal, she operated together with the older Teanntas and provided fire support; she was however not handled very well, ran aground and was hit seven times by a Brazilian coastal battery. Half her crew had to go ashore and silence the battery in a pitched infantry assault, taking heavy losses. She returned to Nuatearman in June 1941 for another round of repairs. During these, it was found out that her keel was cracked and her engine foundations had come loose; the yard director proposed declaring her a constructive total loss. Given the scarcity of operational cruisers, this was rejected, and Cathgangaid was provisionally patched up for use as a training ship, as which she re-entered service in December 1941, although she was restricted to a top speed of 24 knots. She had received a full radar suite and replaced her 13mm machineguns with a total of ten 20mm cannon, and looked like this:
During most of 1942, she remained in the Bauaine on training duty. During the Panama raid, she was briefly placed on active duty as part of a reserve force around the battleships Conaire and Artacain, should the Allies find out that the most valuable Thiarian ships were absent and try to take advantage. In September, she sortied for the battle of Meanhchiorcal, but had to abort when it was found that she was leaking. From September through November, she had another yard period, and additional structural strengthening was worked in to bring her back to limited operational status. She also received some basic ASW gear, including ASDIC, hydrophones, two depth charge racks and two K-guns (the Thiarian equivalent anyway). She again assumed training duties when she came back, and she was the only operational cruiser in the Thiarian inventory that did not participate in the epic battle of Faoigabhar in May 1943. On a training sortie in August 1943, she was engaged by a Recherchean submarine, evading four torpedoes and then sinking it with depth charges; she remained the only Thiarian ship of cruiser size and above ever to hunt down and sink an enemy submarine. By late 1943, she was again judged structurally unsound; her speed was restricted to 20 knots, and she spent most of her time moored. Nevertheless, she was again modernized. Part of her radar suite was replaced, the number of 20mm cannon was increased to 26 and the HA fire control system was replaced by a more modern one. Early in 1944, she looked like this:
Although Thiaria's situation deteriorated from critical to desperate during 1944, Cathgangaid was not called upon for convoy escort duty and lived out the rest of the war relatively quietly. Her crew, including many of the cadet instructors, were infiltrated by the opposition during 1944, and she was one of the first ships to join the mutiny in August 1944. After the armistice, Cathgangaid was decommissioned and not reactivated again. She lingered as accomodation ship till the mid-1950s and was scrapped in 1957.