As the son of immigrants, Donald Trump has his own special relationship with the United Kingdom.
His mother, Mary MacLeod, was born and raised in the village of Tong, on the Outer Hebridean island of Lewis, on Scotland's wild and beautiful north-western fringe.
A less Trumpian upbringing is hard to imagine. Mary's pebble-dashed home was modest to say the least, the traditions of the island strictly and austerely Presbyterian.
Lewis is not a place of multiple marriages and glittering golden towers. It owes more to Calvin than to Mammon, more to Wittenberg than to Vegas.
On Sundays not so many years ago, swings in the island's play parks were chained up. Ferries could not dock, flights were not allowed to land.
Mr Trump is not scheduled to visit Lewis this Sabbath or any other day. He talks rarely and in scant detail about his British mother, who emigrated to New York as a "domestic" in the 1930s, preferring to stress the influence of his hard-driving German father, Fred Trump.
Instead the president and his wife Melania Trump will travel to Trump Turnberry, down the water from Glasgow on the Ayrshire coast, one of his two Scottish golf resorts, where the first couple will stay from Friday until Sunday when they depart for a high-stakes summit in Helsinki.
White House aides won't comment on whether Mr Trump will play golf during his visit, saying only that he will use the time to prepare for the meeting in Finland with Russia's President Vladimir Putin.
But the weather forecast is good - Scotland is enjoying its best summer in living memory - and the links at the newly refurbished complex will surely prove inviting.
Before he can pick up his clubs, though, duty calls in the form of queen and prime minister.
For Mr Trump, the route to the ultimate British clubhouse - in this case Windsor Castle - was strewn with obstacles.
As soon as the property tycoon became president, Theresa May - still prime minister at the time of writing, despite bitter divisions in her Conservative party over the UK's plans to leave the European Union - was off to Washington like a shot.
Mrs May was the first foreign leader to visit the Trump White House, a week after the inauguration in January 2017, and was mocked at home for holding hands with the president and for her obvious eagerness - critics called it desperation - to secure a trade deal with the United States after Brexit.
Nonetheless she persisted with the flattery, playing to Mr Trump's ego and taste for pomp by carrying with her an invitation from Queen Elizabeth for a full state visit to the UK, an honour granted to only two other US presidents, Barack Obama and George W Bush.
Immediately the invitation was controversial. That very day Mr Trump stunned the world - including, it seemed, Mrs May - by announcing a plan to halt all immigration from seven majority-Muslim nations.
The new president's supporters were delighted. Hostility to immigration had been a central plank of Mr Trump's campaign and had arguably played a critical role in his victory.
His approach attracted some sympathy in the UK, not least with those who saw Brexit as an opportunity to regain control of Britain's borders, but Mr Trump's opponents were louder and they spoke with their pens.
In just a few days a petition demanding the withdrawal of the Queen's invitation (such invitations formally bear the monarch's name, but in practice they are extended by the government) gained more than a million signatures.
A month later that number had reached 1.86 million and parliament held a (purely symbolic) debate about whether the visit should be cancelled.
The pressure intensified after Mr Trump broke with diplomatic tradition by intervening in British politics - repeatedly, directly and publicly.
His predecessor Mr Obama did so too, making statements about Scottish independence and Brexit.
But while those comments were controversial, they were in line with the UK government's own views on both subjects at the time. Mr Trump's were not. First, the president outraged many Londoners with his response to a terror attack on the British capital in June 2017.
With seven (later eight) people dead and dozens injured on London Bridge, Mr Trump criticised the response of the city's Mayor Sadiq Khan as "pathetic" because Mr Khan, who is a Muslim, had told people they had nothing to fear from increased police activity in the hours after the attack.
Although privately appalled, Mrs May continued to resist calls for the state visit to be postponed.
Then, last November, the president went even further, retweeting three propaganda videos disseminated by Britain First, a small fascist party on the far right fringes of British politics.
Criticised by the prime minister, Mr Trump hit back, telling her "don't focus on me, focus on the destructive Radical Islamic Terrorism that is taking place within the United Kingdom".
The leader of the opposition Labour party, Jeremy Corbyn, described the retweets as "abhorrent" and "dangerous".
In the uproar that followed Mr Trump was reported to have told Mrs May that he no longer wanted to accept the Queen's invitation.
In the end - after a great deal more marching up hills only to march down again, including a cancelled trip to open the new American Embassy in London - there will be a visit but it will not be a formal state visit, there will be no open carriage ride with the Queen through the streets of the capital.
That would have been a security and public relations nightmare given the promise of mass protest.
Instead the British government is trying to deliver a state visit on the sly. Officially this is a "working visit" but it will include dinner at Blenheim Palace in Oxfordshire, the ancestral home of Winston Churchill; tea with the Queen at Windsor Castle in Berkshire; and a meeting with the prime minister at her country residence, Chequers in Buckinghamshire.
All three venues are easily accessible from, but comfortably outside, London.
There will also be military ceremonies, pipes and drums, and a demonstration of joint US-UK defence capabilities. Mr Trump will not, though, be given the honour of addressing the British parliament, the speaker of the House of Commons John Bercow having strongly objected to the idea because, he said, "opposition to racism and sexism" were "hugely important considerations".
Still, British officials are keen to stress what they say is an "extremely strong" security and intelligence relationship between the two nations and to point out that the UK is one of the few Nato countries already meeting a commitment to spend two per cent of GDP on defence.
The US ambassador to the UK, Robert "Woody" Johnson, said he expected Mr Trump and Mrs May to discuss a range of issues including Russian election meddling, which Moscow has denied despite evidence to the contrary, and the attempted murder of a former Russian spy and his daughter in the Wiltshire city of Salisbury by means of a nerve agent which has now claimed the life of Dawn Sturgess, a 44-year-old mother-of-three.
Items also likely to be on the agenda, according to a briefing from a senior source in the British government, include the Middle East, North Korea and relations with China.
But Downing Street will be looking for one thing above all else: tangible progress on a post-Brexit trade deal between the world's largest and fifth largest economies.
While the EU accounts for about half of the UK's external trade, the US is by far Britain's biggest single trading partner.
The desire for a deal is complicated by the president's mercantilist hostility to free trade and the tariffs which he has imposed on the European Union and others.
"We'd like to get started on the negotiation issue," says the British government source, cautioning "we leave the EU on 21 March 2019… we can negotiate but we can't implement".
While Brexit Britain and Trump's America have in common a desire to return to a supposed golden era of independence, to regain control of their own affairs, to restrict immigration, and to reassert their freedom from the constraints of international institutions, they also have significant disagreements: on climate change and Iran to name two glaring examples.
The shambolic collapse of the recent G7 meeting in Canada was just the latest illustration of the dysfunction operating at diplomacy's highest levels.
Some observers think the UK is in a weak position on this grand stage.
"The irony is that by leaving the EU, the United Kingdom will be less useful to Washington as an ally but it will also need the United States much more," said Jeffrey Stacey, a former State Department official under President Obama.
"So May has been thrown into the arms of the most unpredictable US president in living memory," he added.
Not without protest.
Tens of thousands of people have signed up to demonstrate against President Trump's visit to the UK. Events are planned at Blenheim Palace; in central London; at Chequers; in Ayrshire, Edinburgh and elsewhere.
Strikingly, the mayor of London, Mr Khan, has given permission for a large balloon depicting President Trump as a snarling, orange baby to be flown over Westminster.
The 20ft (6m) high inflatable will rise above the city for two hours.
Leo Murray, who is behind the idea that he calls anti-fascist satire, said "we want to make sure he knows that all of Britain is looking down on him and laughing at him".
British supporters of Mr Trump said the idea was an embarrassment not to the president but to the protesters.
But Mr Murray appeared unconcerned, saying: "Trump Baby will fly!"