Laid down 21 March, 1863, Principe Don Alfonso was renamed Sagunto before she was launched in 1869. Begun as a 100-gun ship of the line, she was converted into an armored frigate during construction. As completed, Sagunto carried eleven rifled muzzleloaders; eight 9" (229mm) Armstrong guns, and three 7.1" (180mm) Trubia guns. Steam and sail propulsion were both provided, making for a top speed of 8 knots. With a long build period, Sagunto was outdated before she was completed, but still served until 1891. She was subsequently broken up.