In the letter, Trump’s hand partially obscures the letter, which reads: “I can only say that it would be … pleasure to extend that invitation once again, in the hope that you … some stage be visiting Turnberry and a detour to a relatively near neighbour might not cause you too much inconvenience. An alternative might perhaps be for you to visit Balmoral.

“There is much on both estates which I think you might find interesting, and enjoy – particularly as my foundation at Dumfries House provides hospitality skills-training for young people who often end up as staff on your own establishments!”

The letter continues: “Quite apart from this presenting an opportunity to discuss a wide range of issues of mutual interest, it would also offer a valuable chance to plan a historic second state visit to the United Kingdom.

“As you will know this is unprecedented by a US President. That is why I would find it helpful for us to be able to discuss, together, a range of options for location and programme content.

“In so doing, working together, I know we will further enhance the special relationship between our two countries of which we are both so proud.”

The letter was hand-signed by the king: “Yours Most Sincerely, Charles.”

“That’s a great, great honour. And that says at Windsor – that’s really something,”

Trump responded by accepting the King’s offer, becoming the only elected political leader in modern history to be invited to two state visits by a British monarch.

Clearly smitten by the invitation, Trump took the time to compliment Charles: “He’s a beautiful man, a wonderful man – I’ve gotten to know him very well, actually, first term and now second term.

“We’ve known each other now for a little while. This is not our first meeting. He loves his country. And so, that’s our common theme. He loves his country. And I love our country.”

The 78-year-old Republican added: “And we also have two countries that have gotten along for the longest period of time. Number one ally on each side. We have France, Australia, a lot of good ones – but we’ve had a long-time relationship, a long time, hundreds of years.”