Donald Trump loves the King, William and Kate, and Keir Starmer should be grateful

God save the King! And William and Kate too. Because it's not Keir Starmer that successfully charmed US President Donald Trump. It's not even David Lammy, even though the former foreign secretary confounded critics by becoming best mates with vice-president JD Vance in a show of expert diplomacy.

The UK's success in wooing the mercurial US President is down to his love of the royal family, and the enormous skill of the King and his late mother in representing our nation. They really are our best diplomats. Dealing with President Trump has been one of the few success stories of Sir Keir's time in Number 10. The UK was the first nation to agree a trade deal with Trump's White House after the President set out his tariff plans, and while it's far from perfect it's better than nothing.

The deal confirmed tariffs of 10% on most UK goods, and plans to end tariffs on British steel products appear to have been shelved indefinitely.

Some critics also point out that the EU eventually negotiated its own deal with Trump, although the base tariff rate for EU goods will be 15%.

So the UK hasn't worked miracles. But we probably got the best deal possible, and we get it before anyone else.

The British government has also succeeded in getting Donald Trumop to pledge some support for a planned peacekeeping force in Ukraine, the so-called Coalition of the Willing. Again, Trump's attitude towards Ukraine remains a huge concern but the UK has managed to nudge him in the right direction.

Sir Keir turned on the charm when he met Donald Trump in Washington in February, and the President praised his "beautiful" accent.

But the Prime Minister had an ace up his sleeve - the King. He invited Mr Trump to a second state visit, and a state visit of course means one head of state - the US President - being hosted by another head of state, which in our case is not the Prime Minister. It's the monarch.

Donald Trump loves it, and said as much as he prepared to get on the plane to the UK for this week's visit where he is a guest at Windsor Castle. Speaking before the visit, he said his trip was "primarily" about the King and the Queen, Camilla. The President said: "They're friends of mine for a long time, long before he was King. I think he represents the country so well. He's such an elegant gentleman and he represents the country so well."

Mr Trump is also a huge fan of the Prince and Princess of Wales.

This isn't new. He was delighted to meet Queen Elizabeth on his first state visit, in 2019.

While our relations with our old friends across the Atlantic aren't perfect, they are far better than they could be. The re-election of Donald Trump posed huge challenges to the UK, but we've met them head on. We can thank the royal family for that.