Said cruiser stood out for its great autonomy, while it suffered from having little armor, mounting only during its first days of life 4 pieces of García Lomas of 100 mm.

[4] Emperador Carlos V[5] was brand new and not yet operational when the Spanish–American War broke out in April 1898, but she was rushed into service and assigned to the 2nd Squadron, commanded by Rear Admiral Manuel de Camara.

Camara's squadron—consisting of Emperador Carlos V, battleship Pelayo, auxiliary cruisers Patiota and Rapido, destroyers Audaz, Osado, and Prosepina, and transports Buenos Aires and Panay – sortied from Cadiz on 16 June 1898, passing Gibraltar on 17 June 1898.

[7] By the time Camara's squadron arrived at Suez on 5 July 1898,[8] the squadron of Vice Admiral Pascual Cervera y Topete had been annihilated in the Battle of Santiago de Cuba, freeing up the U.S. Navy's heavy forces from the blockade of Santiago de Cuba.

After the war, Emperador Carlos V conducted cruises to show the flag, attending naval reviews in foreign countries, most notably including the coronation of King Edward VII of the United Kingdom in 1902.