High Quality Content by WIKIPEDIA articles! HMS Black Prince was the third ship of that name to serve with the Royal Navy. She was the world`s second ocean-going, iron-hulled, armoured warship, following her sister ship, HMS Warrior. For a brief period the two Warrior-class ironclads were the most powerful warships in the world, being virtually impregnable to the naval guns of the time. Rapid advances in naval technology left Black Prince and her sister obsolete within a short time, however, and she spent more time in reserve and training roles than in first-line service.