The wreck of a German battleship that sank off the coast of Kent in 1878, when she was rammed by a friendly vessel trying to avoid two fishing boats, has been added to the National Heritage List for England.
SMS Grosser Kurfurst's armour plating was ripped off and a huge hole was gouged into her side when ramming ship Konig Wilhelm struck the warship during preparations for a training exercises near Folkestone, English Channel.
Germany's stricken ship rapidly disappeared below the waves, losing 284 out of her 300 man crew.
A large memorial in Cheriton Road Cemetery, where many of the bodies pulled from the wreck are buried, has also been given grade-II listed status.
The Department of Culture, Media and Sport issued protections for both on the advice of Historic England.
The warship was one of only three Preussen-class ironclad warships authorised under the naval programme of 1867, approved by the Reichstag to strengthen the German navy.
It was commissioned following the second Schleswig war (1864) involving the weak Prussian navy which had been unable to break a Dutch blockade.
Despite the pressure, however, the newly-built Kurfurst sank in just eight minutes as watertight bulkheads onboard failed to close, according to historian Erich Groner.
The Konig Wilhelm also suffered significant damage in the collision and severe flooding.
Her captain initially planned to beach the ship, but after the pumps managed to hold the flooding to an acceptable level, she instead limped to Portsmouth for emergency repairs before returning to Germany.
Lying four nautical miles off the UK coast, the shipwreck's addition to the National Heritage List means divers are still able to visit, but it now has a new level of protection.
Heritage minister Nigel Huddleston said: 'The listing of the SMS Grosser Kurfurst and the memorial plaque is a fitting tribute to the 284 men who died when the ship sank more than 130 years ago.
'I hope that the increased protection for both sites will ensure that the ingenuity of the early ironclad ships and their influence on modern navy vessels is not forgotten.'
Duncan Wilson, chief executive of Historic England, said: 'This historic shipwreck tells the story of Germany’s increasing naval strength in the late-19th century at a time when Britain and Germany were on friendly terms.
'The SMS Grosser Kurfurst is important as the only non-Royal Naval warship recorded as wrecked in English waters for the period 1860-1913.
'The listing of the associated memorial in Folkestone with its German inscription is a poignant reminder of the loss of nearly 300 crewmen on board. It is right that we continue to remember them.'
Damian Collins, MP for Folkestone and Hythe, also hailed the granting of protection to the wreck and memorial.
He said: 'Folkestone would go on to play an important role in the First World War, as a port of passage for many soldiers travelling to and from the trenches in France and Belgium, which I have worked to commemorate as chairman of the Step Short charity.
'In that spirit, I believe the monument is an important reminder of Anglo-German friendship and solidarity in times of disaster, to be remembered as well as times of enmity.'