Rather than start an AU for every country for whose navy I ever made up a ship, I thought I might just collect them in the Thiaria AU and note the deviations from the OTL that are necessary.
The first one is based on a very real Spanish project of 1914 for a small 20.000-ton battleship with eight 340 or 343mm guns and 20 138 or 140mm guns, with a layout mostly identical to the existing Espana-class.
Unlike most other minor navies, the Spanish Armada preferred quantity over quality, as witnessed by their purchase of the three smallest dreadnoughts ever built. Following this philosophy, they then designed the world's smallest superdreadnoughts. With steel, armour plate and heavy guns available from Thiarian production, the project was not cancelled due to the outbreak of the war. Two were laid down in 1914 (one at S.E.C. in Ferrol and one at Bazan in Cadiz) and another one in 1915 at Ferrol after the last Espana-class ship was launched. Thiarian engineers and designers influenced the general layout (the turrets were arranged in the same way as on the Thiarian Conaire-Class, and they had Thiarian-style complete torpedo bulkheads), but otherwise they had a typically 'english' air to them, resembling a slightly smaller Neptune. The secondary armament was reduced from 20 to 12 barrels due to space restrictions, and even these were arranged awkwardly, and all but the fourth and fifth guns on each side were only usable during a dead calm and at slow speed. They had an early form of director fire control, and their Thiarian 340mm guns were slightly more powerful than the British standard 13,5 inch, so these ships packed quite a good punch for their size of less than 20.000 tons. Speed was 21 knots, and the main belt measured 254mm.
The class ship Regina Victoria Eugenia proceeded only slowly at Cadiz, because the yard there had no experience with large warships; her sister Fernando el Católico however, building at Ferrol, was nearly ready to launch when Thiaria entered the first world war in April 1916 and supplies dried up. As the third ship, the Sancho Garcés, was still at the earliest stages of construction, she was cancelled and the material allocated to the other two. Early in 1917, construction of Regina Victoria Eugenia was suspended at 75% launch readiness and all efforts were concentrated on Fernando el Católico. As the first shipment of heavy guns was already available (the 138mm pieces were made domestically by Hontoria), the Spaniards managed to complete her, using material from the other two, in mid-1918. After the war, construction of Regina Victoria Eugenia briefly resumed, but eventually could not be financed in the general postwar economic baisse.
Fernando el Católico remained the largest ship and flagship of the Spanish navy for the next 40 years, except for a brief period of internment at Bizerta in 1939. She remained loyal to the Republic in 1936 and was briefly renamed 'Progreso', but was torpedoed by an Italian submarine in mid-1937 and then hit a mine on the return leg to Cadiz. She nearly sank, but her Thiarian-designed torpedo protection system saved her (barely). Repairs were extensive and took till October 1938; by that time, the war was nearly over, and she joined the Republican squadron that sailed for Bizerta early in 1939. The French returned her to Spain after the civil war was formally over, and she reverted to her original Name. She was stricken in 1955 and scrapped in 1961.