HMS Royal Oak was a British battleship of the Royal Navy, launched in 1914. It was part of the Nelson-class and served during both World Wars. The ship was equipped with powerful guns and armor, designed for naval warfare. On October 14, 1939, HMS Royal Oak was sunk by a German submarine, U-47, while anchored at Scapa Flow. The attack resulted in the loss of 833 crew members, marking one of the significant early naval losses for Britain in World War II. The wreck remains a war grave and is protected under the Protection of Military Remains Act.