The Principality of Sealand is the happiest place on earth.

[snarp]

No, read the Wikipedia article.

On 2 September 1967, the fort was occupied by Major Paddy Roy Bates, a British subject and pirate radio broadcaster, who ejected a competing group of pirate broadcasters. Bates intended to broadcast his pirate radio station, Radio Essex, from the platform.

In 1968, British workmen entered what Bates claimed to be his territorial waters in order to service a navigational buoy near the platform. Michael Bates (son of Paddy Roy Bates) tried to scare the workmen off by firing warning shots from the former fort.

As Bates was a British subject at the time, he was summoned to court in England on firearms charges following the incident. But the court ruled that as the platform (which Bates was now calling "Sealand") was outside British jurisdiction, being beyond the then three-mile limit of the country's waters, the case could not proceed. In 1975, Bates introduced a constitution for Sealand, followed by a flag, a national anthem, a currency and passports.

I don't think any of the clients have ever claimed that their crimes took place in sovereign nations and then actually made a flag. Just the first part.

In August 1978, while Bates and his wife were in England, Alexander Achenbach, who describes himself as the Prime Minister of Sealand, hired several German and Dutch mercenaries to spearhead an attack of Roughs Tower. They stormed the tower with speedboats, jet skis and helicopters, and took Bates' son hostage. Bates was able to retake the tower and capture Achenbach and the mercenaries. Achenbach, a German lawyer who held a Sealand passport, was charged with treason against Sealand and was held unless he paid DM 75,000 (more than US$35,000 or £23,000).

The governments of the Netherlands, Austria and Germany petitioned the British government for his release, but the United Kingdom disavowed his imprisonment, citing the 1968 court decision. Germany then sent a diplomat from its London embassy to Roughs Tower to negotiate for Achenbach's release. Roy Bates relented after several weeks of negotiations and subsequently claimed that the diplomat's visit constituted de facto recognition of Sealand by Germany.

Following his repatriation, Achenbach and Gernot Pütz established a "government in exile", sometimes known as the Sealand Rebel Government, or Sealandic Rebel Government, in Germany. Achenbach's appointed successor, Johannes Seiger, continues to claim via his website that he is Sealand's legitimate ruling authority.

And

2007–2010: Sealand was offered for sale through the Spanish estate company InmoNaranja. Since a principality cannot technically be sold, Sealand's current owners plan to transfer "custodianship". The asking price is €750 million (£600 million, US$906 million).

2012: Sealand online casino is expected to be opened by late 2012.[dated info]

9 October 2012: Roy Bates, Prince of Sealand, died after suffering Alzheimer's disease for several years. He was succeeded by his son Michael.

So I'm picturing Roy and Michael Bates as Jake and Jade, and Achenbach and Seiger as Dirk and Dave. Just, like, invading the place every year for their birthday present.