In August 1978, Alexander Achenbach, a German lawyer claiming to be the Prime Minister of the self-proclaimed Principality of Sealand, orchestrated an armed takeover of the HM Fort Roughs platform off the English coast while its founder, Paddy Roy Bates, was away. Achenbach hired German and Dutch mercenaries to seize the concrete fort and held Bates's son, Michael, hostage. Days later, Roy Bates launched a daring helicopter counter-strike, retook the platform, and captured the invaders.
While the mercenaries were released, Achenbach held a Sealand passport and was charged by Bates with high treason under 'Sealand law.' Faced with Achenbach's imprisonment and a demand for a $35,000 fine, the West German government sent a diplomat from its London embassy directly to Sealand to negotiate his release. Following the diplomat's visit, Bates released Achenbach and subsequently claimed that West Germany's direct diplomatic engagement constituted de facto recognition of Sealand as a sovereign state.
From a legal standpoint, mainstream international legal scholars overwhelmingly rejected this assertion. Under public international law, formal state recognition requires clear intention; routine consular negotiations conducted to secure the release of a national stranded abroad do not satisfy the criteria for legal recognition under the Montevideo Convention. Furthermore, the UK government maintained that Fort Roughs lay within British territorial waters or international waters without recognized statehood.
Despite these legal realities, the 1978 counter-coup trial remains one of the most famous legal anomalies in modern micronational history, frequently cited in debates over the constitutive versus declarative theories of statehood.