According to this wikipedia article on the history of the channel islands, "In 1483 a Papal bull decreed that the islands would be neutral during time of war." What was the reason for this? Why did the Pope think this was an issue worth his time? How come it was abolished in 1689 following the Glorious Revolution?
Interestingly, the claim is not cited in the wikipedia article I linked nor the list of Papal Bulls article so it may have been fabricated by the author of the article, but that seems unlikely.
"The Channel Islands, 1370-1640: Between England and Normandy" by Tim Thornton (at least the parts of it available on Google Books) dates the bull to 1480/1481, and determines the original intent was to battle piracy, with "neutrality" being read back into the record at a later date.