It broke away from the UK when Alex Salmond was only a boy, but the world's smallest independent 'state' is now mourning the loss of its ruler.

Sealand, a 5920 square feet former Second World War anti-aircraft fort off the south coast of England, broke away from the UK in 1967.

The move was at the behest of its sovereign, 'prince' and founder Roy Bates, who has died at the age of 91.

The retired Army major established the country after getting involved in the pirate radio movement of the 1960s and setting up Radio Essex on the Knock John forts in the Thames Estuary.

After being prosecuted under the Marine Broadcasting Offences Act, Mr Bates moved his family to the Roughs Tower island fort, seven-and-a-half miles off Felixstowe in the North Sea, according to the country's official website.

On his wife Joan's birthday, September 2, 1967, Mr Bates declared the fort independent from the UK and bestowed her the title of "princess". For the next four decades he ruled the waves from the fort.

In a 1980s television interview, Mr Bates said: "I might die young or I might die old, but I will never die of boredom."