Castelfidardo was the third of four Regina Maria Pia-class ironclad warships built in French shipyards for the Italian Regia Marina (Royal Navy) in the 1860s. Castelfidardo was laid down in July 1862, was launched in August 1863, and was completed in May 1864. She and her three sister ships were broadside ironclads, mounting a battery of four 8-inch (200 mm) and twenty-two 164 mm (6.5 in) guns on the broadside.