A prototype submarine which sank off the Sussex coast has been given protected wreck status.
Sister ship the Holland number one was salvaged in 1982
The Holland number five was the last of five submarines built by the British Admiralty in the 1890s to test the potential of the submarine as a weapon.
It was launched in 1902 and foundered off Beachy Head, East Sussex in 1912.
The order, which comes into effect on Tuesday, is aimed at protecting the site from damage through unauthorised interference from divers.
The Holland number five - and its four predecessors - were built by the Holland Torpedo Company and it contained one of the first periscopes ever designed.
The wreck was discovered in 2000 and after surveys by archaeological divers, it was identified as the Holland number five in April 2001.
The Holland number one is the only other of the five submarines still in existence, having been salvaged in 1982.
It is on show at the Royal Navy Submarine Museum at Gosport in Hampshire.
Heritage minister Andrew McIntosh said: "The Holland number five played a short but significant role in the evolution of the British submarine and the survival of this boat gives a unique opportunity to study the technology of the time including the possible prototype of the submarine periscope.
"The Holland number five is thought to be intact and in good condition.
"I am pleased that this order will preserve the wreck site allowing proper study of the vessel and preventing any vandalism by trophy hunters."
The protection order can be made under the Protection of Wrecks Act 1973 and makes it a criminal offence for anyone to interfere with the site without authority.