"Principality of Sealand", HM Fort Roughs, 'Princess' Joan Bates (1967-2016), Pattern 20-Sealand Dollars, 1975 (KM X2), very fine or better, rare.
In 1967, Patrick and Joan Bates occupied the former military platform HM Fort Roughs off the Suffolk coast and declared the site independent, styling themselves Prince and Princess in the process. The micronation has no international recognition but has continued to be claimed by their son Michael, as well as appointment Barons of the Principality in the years since, including such celebrities as Ed Sheeran.
Estimate: £100 - £130