A handwritten note from Prince Philip in which he apologised to the then US president Richard Nixon for a "lame" toast in which he forgot to propose his host’s health has been made public for the first time.
The Duke of Edinburgh wrote to the 37th American leader that he’d woken "in a cold sweat" when he released his breach of etiquette at a White House dinner held in his honour during a solo visit to the US in 1969.
During such events, the invited guest usually offers a toast to the president’s health and success.
The letter was uncovered by archivists at the Richard Nixon Presidential Library and Museum in Yorba Linda, California.
Writing from Greenland following his trip on 7 November, Philip wrote: "After the brilliance of the other speakers and yourself, I am afraid my contribution was very lame."
He added: "That night I woke up in a cold sweat when I realised I had forgotten to propose your health!"
Jim Byron, executive vice president of the Nixon Foundation, said: "I think the letter itself shows the character of Prince Philip that so much of the public in the UK and across the Commonwealth, and really across the world, have come to admire."
He said the letter was discovered before the coronavirus pandemic – but only made public this week, as a way of marking the duke’s death.
"It expresses some private feelings of a moment in time that the public really doesn’t always get a chance to see," Mr Byron added.
The duke also mentioned travelling to New York, where he was interviewed by Barbara Walters for NBC’s Today show.
Philip wrote: "The weather in New York was horrible but otherwise all went well, and I found Miss Walters particularly charming and intelligent. I hope we did a good piece."
The all-male guest list for the "stag" dinner included vice president Spiro Agnew, most of the members of Mr Nixon’s cabinet, and non-governmental notables such as business tycoon Ross Perot and British-born comedian Bob Hope.
Mr Byron said Mr Nixon almost certainly replied to Philip’s letter, but, with the library archives remaining closed because of COVID-19, what he might have written is unknown – as are the duke’s remarks, other than failing to wish Mr Nixon good health.
The dinner came a day after Mr Nixon delivered his famous "silent majority" speech in which he urged the US to unite behind the continuing war in Vietnam until his administration could achieve "peace with honour".
Mr Byron said top aide HR Haldeman, who later went to prison for his involvement in the Watergate scandal, noted in his diary how happy the president had been that night, given that his address had been positively received.
Philip had met Mr Nixon on a number of occasions prior to the dinner.
The Nixons also gave the royal couple a tour of Washington‘s sites when they made a state visit to the US in 1959.
"Philip, by all measures, he was being kind," Mr Byron said of the letter. "And really expressing so much of his character."