Prince Charles asked New Zealand to stop making fun of him after he fell off a horse because he was getting sensitive about it.
A letter by the Prince written when he was a young man reveals his determination to "make the New Zealanders laugh out the other side of their faces" for mocking his head-first tumble in a polo match, according to the Daily Mail.
The younger Charles also said he might go "demented" if he had to answer another child's question about "what it was like to be a prince" while on the royal tour, and expressed frustration about the "nonsense" he was having to put up with.
The letter, which is set to be sold at auction, was written in April 1981 and touched on a variety of topics about the trip. It includes the line: "Kindless, fallacious remarks and references about me falling off horses are starting to get through to me. It seems as though the main thing they know about me out here!"
The irritable jibes was prompted by the Prince falling off his horse three times within six weeks, the most recent at the time being a tumble at a match near Sydney in Australia.
The revelations follow the publication of the Prince's correspondence in 2010 which, after five years of legal battles, were made public following a Freedom of Information request. They showed he had lobbied ministers on a range of political and personal concern issues including agriculture, the plight of the albatross and architecture, understood to have angered Buckingham Palace.
Since then, the government has announced it will be reviewing the Freedom of Information Act to "protect" some kinds of information from being made known.
When asked about the letter, Buckingham Palace said it did not issue comments on private correspondence.