A country on a barge. Another in the sky. The strange world of micronations

Founded on 13 April 2015, Liberland is what happens when three disgruntled libertarians meet an unclaimed piece of land. The land in question is a three square-mile plot of no-man's land between Serbia and Croatia. Currently inhabited by one dilapidated building, one wouldn't expect Liberland to appeal to anyone. But when the Liberland website went online, the prospect of a tax-haven country with a motto of 'live and let live' evidently appealed to a lot of people. In just over a week, 22,000 applications for citizenship flooded in.

All the interest it generated made both Croatia and Serbia wake up to their new-found neighbour. And now they're doing their best to kill it in the crib. Serbian and Croatian border patrols have made accessing Liberland near-impossible. How impossible? Well, the President of Liberland was arrested by Croatian border police for trying to get into Liberland and despite his release the future looks grim at best.

"Who saw that coming?" asked no one ever.

With a name more suited to an aquarium than a country, Sealand consists of a single offshore platform 12 kilometres off the coast of England. Looking like a failed prop from Waterworld, it considers itself the world's smallest country - even if no one else really considers it a country at all.

It was founded in 1967, when Paddy Bates seized control from a group of competing pirate radio broadcasters. Once he had control, Bates decided to dream big and eventually wrote Sealand's constitution in 1975 to establish its sovereignty. Oh, he also proclaimed himself prince.

Far from being unwanted, Bates' little kingdom was the target of an unsuccessful coup by mercenaries led by his own Prime Minister. The now-infamous Pirate Bay also unsuccessfully tried to buy Sealand to avoid Swedish copyright laws.

After 'Prince' Bates' death, his son Michael now rules, though he does it from England and his only subjects are the caretakers he employs to look after Sealand.

While the first two micronations on our list took advantage of dubious territorial claims, Hutt River is the product of a Boston Tea Party-esque revolt. After trying to fight Australia's wheat quota laws back in the 1960s, Leonard Casely decided it was easier to just secede from Australia. And secede he did in 1970.

He now runs his 18,500-acre farm as the Principality of the Hutt River and has crowned himself 'His Royal Highness Prince Leonard'. With citizenship available online, Hutt River boasts of 18,000 citizens, though only members of Casely's family actually live there.

Hutt River also boasts an army (consisting of Casely's children and grandchildren) and a navy (even though it's landlocked) and had even declared war on Australia in 1977 for a few days. Still, for all the craziness, the Principality of the Hutt River just celebrated its 45th anniversary. And not every micronation gets to say it's the second biggest country on a continent.

Unlike the others that exist on Earth, the founder of Celestia had far, far grander ideas. In 1949, James Thomas Mangan officially laid claim to the entire universe. Well, all of it except Earth, because, you know, that was already taken.

A micronation of one, he didn't take intrusions into his territory lightly and wrote scathing letters to both the United States government as well as the Russian government as they battled it out in the space race.

Amazingly, Mangan lobbied hard enough to get the Celestia flag unfurled at the United Nations' building in New York. Still, Mangan's claims came to naught, with the Outer Space Treaty that was signed in 1967 ultimately spelling an end to all claims made on celestial bodies.

Celestia died with Mangan, and for those of you thinking his life's work amounted to nothing, how many of you can say you ruled the universe?

With a name derived from the 'American Empire' and a flag parodying Canada, the Aerican Empire is an experiment in unbridled hilarity. Begun in 1987 by Canadian citizen Eric Liz, the country currently claims territory all the way from Australia to an imaginary planet as well as a whole bunch of places in between (including bits of Pluto and Mars).

While the Empire was originally entirely fictitious, it has gradually moved towards establishing itself as a political entity. Evidently, they didn't think seriousness was a major criterion for this. The Empire also has its own religion centred on the worship of 'The Great Penguin' even though, like most things Aerican, it's largely in jest.

With downloadable passports and stamps, they even have their own holidays, except they're not called holidays - they're called niftydays because they aren't technically holy. With niftydays such as Procrastinator's Day, we wonder why it doesn't have more citizens.