The structure Sealand is built upon is technically a very large sunken ship, due to the way it was deployed. It was built in 1942 on a pontoon barge at Red Lion Wharf as a superstructure of two hollow concrete towers topped with a deck, upon which other structures could be added. The twin towers were divided into seven floors each, which provided dining and sleeping accommodations, and storage areas for generators and munitions. When it was completed, three tugboats towed it out of to the Rough Sands sandbar six miles off the coast, where it's pontoon base was deliberately flooded to allow the structure to settle onto the sea floor.
Once Roughs Tower's wartime duties were done, and the Royal Navy had cleaned it out, it sat unoccupied for a number of years. Its first new tenants appeared sometime in 1967, when a group of pirate radio broadcasters-- operating out of nearby anchored ships-- wanted a place to land their resupply helicopters. But in September of that year, a competing pirate broadcaster named Roy Bates physically evicted Roughs Tower's illegal tenants, and became a squatter himself.
Nonetheless, Roy Bates maintained his control of Roughs Tower, and declared it the Principality of Sealand; a sovereign, independent state. This was after consulting with an attorney who found a loophole allowing Roy to claim the fort due to fact that it was in international waters, and that it was up for grabs due to "dereliction of sovereignty." Since it was outside of England's legally controlled area there was nothing the Royal Navy could do about this, but they did demolish another fort that stood beyond the 3-mile boundary, to prevent a similar takeover there.
The following year, the legitimacy of this self-declared state would be put to the test when Michael Bates fired a warning shot at a British Trinity House vessel which approached the tower. This led to Roy Bates' arrest when he next arrived on the mainland. The case against Roy and Michael Bates was brought to court, where the judge ruled that Sealand was outside of British jurisdiction, therefore no ruling could be made against the Bates boys for their actions. The authorities decided not to appeal this ruling, as it may have led to an undesirable precedent.
In August of 1978, about ten years after independence was declared, Roy was approached by a consortium of German and Dutch diamond merchants who wanted him to fly to Austria to entertain a business proposition. Upon their arrival, he and his wife Joan were met by five men who arranged for a meeting later that day, but the meeting time came and went without any word from the men. Concerned, Roy and his wife tried to make contact with their son Michael at Sealand, but since there was no phone or radio on the artificial island, they had to call local fishermen and the coast guard. "I saw a big helicopter hovering over Sealand," one of them reported. Things were beginning to look very suspicious.
Their worries were confirmed when they finally heard from Michael, many days later. A helicopter had arrived at Sealand, claiming to have a Telex from Roy. But upon landing, they took the platform by force with the assistance of the "Prime Minister" Roy had appointed, a man named Alexander G. Achenbach. The invaders locked Michael in a cell for three days without food or water, then put him aboard a Dutch vessel which dropped him off in Holland with no money and no passport.
Not much exciting has happened there since the miniature war of '78, though Roy was approached by a group of Argentineans during the Falklands War in 1982; they wanted to buy Sealand and set up camp "right on Britain's doorstep." He sent them away.
Today, Sealand's sovereignty and legitimacy are not recognized by any traditional States, however it is perhaps the best-known micronation in the world even though its inhabitable area is only 550 square meters. It is quietly tolerated by the UK, which still claims ownership and control of the sandbar upon which Sealand sits. Recently declassified documents show that the UK drafted plans to take the tower by force over 30 years ago, but such plans were not implemented due to the potential for loss of life, and the public relations disaster that would have followed.
Sealand's electrical generators are now tasked with powering the servers for HavenCo, a data hosting services company which was started on Sealand in the year 2000. The Bates are leasing the country exclusively to HavenCo Limited, which offers "unparalleled security and independence to users who wish to take advantage of its Internet colocation services."
No smoking or drinking are allowed in the Principality, and no one is allowed more than three five-minute showers per week in the interest of conserving freshwater; much of which is collected from rain. Its population rarely exceeds five people, and in the sake of security, visitors are unwelcome. Until 2001, HavenCo was run by a man named Ryan Lackey who said, "It's been good for us because a lot of people are afraid of the very draconian laws being passed in the US, and they want to get out in advance of those." HavenCo claims it will destroy a customer's server if it's ever forced to hand over a customer's data to the authorities.
Sealand's original royalty are no longer residents at Sealand, instead living on the British mainland due to their declining health. But there may be some big changes in store for the micronation, including the possibility of increasing the size of the island to allow for a hotel/casino resort.