Construction of Jaime I was authorized by the Navy Law of 7 January 1908. She was laid down on 5 February 1912, launched on 21 September 1914. Her completion was greatly delayed by a shortage of materials from the United Kingdom during World War I, and she not completed until 20 December 1921, almost 10 years after she was laid down and almost 14 years after her construction was authorized.
In order to avoid rebuilding existing docks, she was constructed with a shorter hull than a purely rational design required, and her class were the smallest dreadnought-type battleships ever built. Amidships freeboard was only 15 feet (4.6 m), and the main battery guns were 24 feet 6 inches (7.5 m) above the waterline.
With a single stack amidships, two tripod masts, and small superstructure, the Jaime I had a broadside of eight 12-inch (305-mm) guns, each weighing 67.1 tons, firing an 850-pound (385-kg) shell at a muzzle velocity of 2950fps (902m/s) with a maximum range of 23,500 yards (21,500 meters, or 11.6 nautical miles), at a rate of fire of one round per minute. The four twin turrets were arranged with "A" and "Y" on the centerline, and the other two turrets in the wings ("B" to starboard, "Q" to port). This was done in preference to superimposed turrets, as was done in the SouthCarolinas, to save weight and cost.Jaime I was able to fire a full broadside, and (unusually) employ six guns in pursuit or retirement. The secondary battery was poorly laid out in casemates along the hull too close to the waterline.
Built for coast defense and national pride, more than combat, the JaimeI and her sisters provided Spain with formidable ships at reasonable cost. Unfortunately, due to rapid technological change at the time and her very lengthy construction time, Jaime I wasobsolescent before completion.
Jaime I saw action against insurgents in Morocco in the Rif War during the early 1920s, and was damaged by a coastal battery in May 1924. She fought on the Republican side in the Spanish Civil War. During that conflict, she was damaged by a Nationalist air attack at Malaga on 13 August 1936.
On 17 June 1937, while at Cartagena, she was wrecked by an accidental internal explosion and fire. She was refloated, but determined to be beyond repair. She was officially discarded on 3 July 1939