Newly declassified documents show that Britain claimed the rocky outpost of Rockall in the 1950s over fears a missile base on the Outer Hebrides would be spied on.
The post volcanic inlet lies 230 miles off the coast of the Hebridean island of South Uist, which has been used a missile testing base for decades.
Rockall was a disputed territory between Ireland and the UK for many years, although the issue appeared to have been resolved as of 2014.
The granite rock is only 100ft wide and is completely uninhabited, save for a number of times it has been stayed on for a challenge or for protest.
Now, Nato documents from 60 years ago show that the then Government feared ‘hostile agents’ could use Rockall to spy on the missile site in the Hebrides.
A tiny team were sent in the Autumn of 1955 by the Royal Navy to plant a Union Flag, install a plaque, and officially claim the 70ft high rock as British territory.
The documents, first seen by the BBC, reveal: “This decision of the UK Government was connected with the fact the government had recently decided to set up a guided missile range in South Uist, in the Outer Hebrides.
This government wished to guard against the possibility of hostile agents installing themselves on the island in order to observe the effects of the test on the South Uist range.”
Scottish explorer Nick Hancock broke the record for occupying the tiny rock in 2014 when he stayed there for 43 days.
It has also been feared recently that Brexit could again open the door to a territorial dispute.