In 1862, the Italian government under Prime Minister Urbano Rattazzi and his naval minister Carlo Pellion di Persano made the decision to build a fleet of ironclad warships. The Italian fleet had already acquired a pair of small, French-built armored frigates of the, and two more vessels of the had been ordered from the United States. Five more ironclads were ordered from foreign shipyards, three wooden steam frigates already under construction were converted into armored ships, and four more ironclads were ordered from Italian shipyards. The two Principe Amedeo-class ships were the last two of this first generation of Italian ironclads. The design for Principe Amedeo was prepared by Inspector Engineer Giuseppe De Luca. He had initially planned on using entirely wooden hulls for the ships, but had changed to composite wood and iron construction by the time the ships were laid down.
The two ships differed slightly in size. Principe Amedeo was 79.73m (261.58feet) long between perpendiculars, while Palestro was 78.82m (258.6feet) long. Principe Amedeo had a beam of 17.4m (57.1feet) and a draft of 7.9m (25.9feet); Palestros beam measured 17.3m (56.8feet), and she had a draft of 8m (26feet). Both ships displaced 5761LT normally, but Principe Amedeo displaced 6020LT at full load and Palestro reached 3218LT. The ships had an inverted bow with a naval ram below the waterline. Their superstructure was minimal, consisting primarily of a small conning tower forward. They had a crew of 548 officers and men.
The ships' propulsion system consisted of one single-expansion steam engine that drove a single screw propeller, with steam supplied by six coal-fired, cylindrical fire-tube boilers. The boilers were trunked into a single funnel. The lead ship's engine produced a top speed of 12.2kn at 6117ihp, while Palestro made 12.85kn at the same horsepower. They could steam for 1780nmi at a speed of . The ships were barque-rigged to supplement the steam engine; Principe Amedeo and her sister were the last rigged ironclad to be built by Italy. The ships' sail area were for Principe Amedeo and 37361square feet for Palestro.
Palestro and Principe Amedeo were both armed with a main battery of six 100NaN0 guns, though they were mounted differently in each ship. Principe Amedeo carried hers in a single armored casemate located amidships, while Palestros guns were mounted in three armored casemates. The first was located forward, toward the bow, the second and third were placed close to the stern on each side of the ship. Both ships also carried an 110NaN0 gun that was mounted forward as a bow chaser. Later in her career, Principe Amedeo received a secondary battery of six 2.90NaN0 guns and six machine guns, along with two torpedo tubes.
The two ships were protected by iron belt armor that was 8.70NaN0 thick and extended for the entire length of the hull. The casemates were protected with 5.50NaN0 of iron plating, and the small conning tower had 2.40NaN0 thick iron plates.
| Builder | Laid down | Launched | Completed | |
|---|---|---|---|---|
| Italian: [[Regio Cantiere di Castellammare di Stabia]] | August 1865 | 15 January 1872 | 15 December 1874 | |
| Italian: [[Arsenale di La Spezia]] | 30 September or 2 October 1871 | 11 July 1875 |
Neither ship had a particularly eventful career. They were completed too late to take part in the final stages of the wars of Italian unification. Instead, they were assigned to the Italian colonial empire, with occasional stints in the main Italian fleet. In 1880, Palestro took part in a naval demonstration off Ragusa in an attempt to force the Ottoman Empire to comply with the terms of the Treaty of Berlin and turn over the town of Ulcinj to Montenegro. The following year, Principe Amedeo was involved in a collision with the ironclad during a hurricane, though neither ship was damaged.[1]
In the late 1880s, both ships were withdrawn from frontline service and employed as headquarters ships for the defense of Taranto - Principe Amedeo - and La Maddalena - Palestro. Principe Amedeo was stricken from the naval register in 1895 and used as an ammunition depot ship in Taranto until 1910, when she was sold for scrap. Palestro was employed as a training ship between 1894 and 1900, when she too was stricken from the register. She was broken up between 1902 and 1904.