In 1967, retired army major and self-made millionaire Paddy Roy Bates proclaimed himself ruler of the Principality of Sealand on a World War II Maunsell Sea Fort in the North Sea, off the East Anglian Coast – and began the peculiar story of the world's most stubborn micronation. Having fought off attacks from the British government and armed mercenaries for half a century – and thwarted an attempted coup that saw the Prince Regent taken hostage – the self-proclaimed independent nation still stands. It has its own constitution, national flag and anthem, currency, and passports – and offers the esteemed titles of ‘Lord' or ‘Lady' to its loyal patrons.

Incorporating original interviews with surviving members of the principality's royal family, Sealand recounts the outrageous attempt to build a sovereign kingdom by a family of rogue, larger-than-life adventurers on an isolated platform in the freezing waters of the North Sea.