But the sturdy Brit recovered from his injuries, married a beauty queen and prospered in business — all before embarking on the greatest adventure of his life.
In 1967, he founded the Principality of Sealand on an abandoned North Sea military platform six miles off the British coast. He issued passports, stamps and coins, commissioned a national anthem and installed himself as its sovereign ruler.
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In short order the self-styled Prince Roy clashed with British authorities, who hauled him into court only to see the emboldened royal return to his 5,000-square-foot nautical kingdom. Later he was overthrown in a coup but took back his republic in a helicopter raid led by a stunt pilot for James Bond movies.
Bates, who ruled his mini-nation for 45 years, died Tuesday in Essex, England. He was 91 and had Alzheimer's disease, according to an announcement on the Sealand website.
"My husband should have been born 300 years ago," his wife, Joan Bates, once told The Times. "He's an adventurer, an entrepreneur. The challenge is what it's all about."
Born in a London suburb on Aug. 29, 1921, Bates was the son of a meat market salesman and his wife. Lying about his age, he joined the International Brigade at 15 to fight in the Spanish Civil War. During World War II, he was a major in the British infantry who saw action across Europe and Africa.
After the war, he went into the meat business in Ireland, imported latex from Malaysia, ran a chain of butcher shops and established a fleet of fishing boats on the Essex coast.
In the mid-1960s, he developed a fascination with pirate radio, joining a slew of unlicensed broadcasters eager to break the British Broadcasting Corp.'s monopoly through offshore operations. Eager to feed a growing market for pop music, some of the pirates broadcast from ships in international waters. Others took over old World War II sea forts.
Bates knew about the forts from his fishing excursions. In 1965 the handsome man with sea-green eyes and frothy white brows led a crew to an old Royal Navy gun platform, ousted its occupants and claimed it as the base for his 24-hour Radio Essex. When the British government clamped down on him, he moved a few miles to Fort Roughs, a rusting steel-and-concrete artillery platform unused since the 1950s.
Bates' broadcasts favored crooners like Frank Sinatra, but as the father of teenagers caught up in rock music, he considered more raucous options. One of them was an unknown band calling itself the Rolling Stones, who came by one day to play a tape of their music for Bates. His reaction, Bates' son Michael recalled in the London Independent in 2004, was less than charitable. "What a load of bloody crap," Bates muttered before ordering the future rock stars out.
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In 1967, a law took effect making it illegal for pirate radio operators to employ British citizens. For Bates, there was only one way to answer such a hostile act.
On Sept. 2, he founded Sealand, declaring it a tax-free nation exempt from British income taxes. He became Prince Roy and, because it was his wife's birthday, made her Princess Joan. With their children they took up residence on the decrepit relic. Its motto was "E Mare Libertas — From the Sea, Freedom."
"Roy was a fighter," said Sean Sorensen, a screenwriter in Venice, who secured the movie rights to Bates' story several years ago. "Sealand started as a business venture but became about so much more."
Not long after Sealand's birth, shots were fired in a confrontation with British authorities, landing Bates in court. But the judge handed the latter-day buccaneer an unexpected victory when he concluded that Sealand was in international waters and therefore beyond the jurisdiction of British laws. Bates took the ruling as de facto recognition of his principality's independence, although it has never been recognized by Britain or any other country.
In 1978, a group of would-be German investors lured Bates and his wife to Vienna, then seized Sealand in their absence. The monarch and his supporters swooped back in on an old war buddy's helicopter and captured the hijackers. They kept one as a prisoner, forcing him to make Sealanders' coffee and clean the loos for nearly two months until Bates finally kicked him out.
All remained relatively well in the rogue state until the late 1990s, when counterfeit Sealand passports began turning up in strange hands, including the German owner of the Miami houseboat where the murderer of designer Gianni Versace took his own life in 1997.
Spanish authorities later determined that the fraud was perpetrated by the German marauders who avenged their 1978 defeat by appropriating Sealand's name and symbols and charging hefty prices for the counterfeit documents.
In 2005 Bates and his wife retired to Spain, returning to England when his health deteriorated. Besides his wife and son, he is survived by a daughter and four grandchildren.
Sealand, which generates revenue hosting servers for Internet businesses, is now run by his son.
"I might die young or I might die old," Bates told an interviewer in the 1980s, "but I will never die of boredom."