Image caption Roy and Joan Bates declared themselves Prince and Princess of Sealand in 1967

A man who established his own independent state on a former military platform in the sea off East Anglia has died at the age of 91.

"Prince" Roy Bates set up the Principality of Sealand in international waters seven miles off the coast of Felixstowe, Suffolk.

Mr Bates died on Tuesday at a nursing home in Leigh-on-Sea, Essex.

His son "Prince" Michael said he would be remembered as a man who stood up to the establishment.

World War II veteran Roy Bates was involved in setting up the pirate radio station Radio Essex at a different offshore platform before moving to Roughs Tower, which he renamed Sealand and declared it as independent territory in 1967.

The tower was built as a platform for anti-aircraft guns during World War II.

'Both armed'

Michael Bates, who lives in Southend, Essex, said: "He was an extremely intelligent and active man and he developed Alzheimer's, which he would have absolutely hated, and he barely recognized his family over the last few years.

Image caption Sealand is about seven miles off the coast of Felixstowe and Harwich

"My father will always be remembered for shaking up the establishment with pirate radio, declaring Sealand's independence and confronting the Royal Navy and other foreign governments."

During the Bates' time on the platform, they saw off an attempt by the Royal Navy to evict them, and an attempt by a group of German and Dutch businessmen to seize control of the platform by force in 1978.

Michael Bates said they were taken to Holland and he returned with his father to successfully recapture Sealand and the five men who were on it.

He said: "We were both armed and that's certainly one of the most memorable days I spent with him."

Britain extended its territorial waters in 1987 to include Sealand.

Roy Bates' funeral service is due to take place at Southend-on-Sea Crematorium next Wednesday.

As well as his son, Roy Bates leaves his widow "Princess Joan", his daughter Penny and four grandchildren.

Sealand, now run by Michael Bates, is used as a base for internet servers and other business ventures.