The Queen has played a pivotal role in the UK’s relationship with America over the decades.
Elizabeth II has met every US president of her reign so far – except for one.
Lyndon B Johnson, who took over in 1963 following John F Kennedy’s assassination, never crossed paths with the Queen.
Donald Trump’s state visit, which begins on Monday, is the third by an American president to the UK, following George W Bush’s in 2003 and Barack Obama’s in 2011.
Here’s a look at the Queen’s encounters with US leaders over the years:
Harry S Truman
In 1951, a young Princess Elizabeth – unknowingly three months away from becoming Queen – went to Washington and saw President Harry S Truman, who was still in the Oval Office when she acceded to the throne.
Dwight D Eisenhower
During her first state visit to America in 1957, now Queen, she met Dwight D Eisenhower.
They met again in Canada in 1959 and travelled on the Royal Yacht Britannia together.
The Queen was said to have had an affectionate relationship with Mr Eisenhower, who was even invited to stay at the Queen’s Scottish hideaway, Balmoral Castle.
John F Kennedy
The glamorous JFK and his wife Jackie dined with the Queen and the Duke of Edinburgh at Buckingham Palace in June 1961.
Jackie Kennedy was invited to lunch with the Queen at the palace a year later while she was on a private visit to London, and the pair bonded over their love of horses.
Lyndon B Johnson
Mr Johnson, then vice president, took over after Mr Kennedy’s assassination in 1963.
He was president until 1969 – but the Queen never met him, and he died in 1973.
Richard Nixon dined with the Queen at Buckingham Palace in February 1969.
The Queen also met Mr Nixon at Chequers in October 1970 and was photographed with him outside the prime minister’s official country residence.
In 1976, during the US bicentennial, the Queen met Gerald Ford in the US, and they danced together at the state dinner in the White House.
In 1977, the monarch was pictured in a billowing, wide-sleeved yellow gown alongside Jimmy Carter, in a black tie and tuxedo, when he came to London.
Ronald and Nancy Reagan stayed at the Queen’s favourite home, Windsor Castle, in 1982.
The monarch and the former film star shared a bond through their love of horses and rode side by side in Windsor Great Park.
Both looked relaxed and informal in jodhpurs and riding boots, with the Queen dressed down in her headscarf.
She also met Mr Reagan during an official visit to America’s West Coast in 1983.
George Bush Snr
George Bush Snr had lunch with the Queen at Buckingham Palace in 1989.
She also visited him in the US in 1991 – the trip that led to “Podiumgate” – when all that could be seen of the Queen above the lectern when she was delivering an address on the White House lawn was her hat.
Bill Clinton and his wife Hillary met the Queen several times, including in December 2000 when, along with daughter Chelsea, they visited Buckingham Palace.
George W Bush
George W Bush visited the head of state at the palace in July 2001.
Two years later, in November 2003, Mr Bush paid an official state visit – the first by a US leader – and the Queen gave him a wide smile as they shook hands at her London residence.
He was honoured with a state banquet in the palace ballroom.
The Queen’s London home had been the site of a major security breach the same day, when Daily Mirror reporter Ryan Parry revealed he had been working undercover as a footman at the royal residence for two months.
Parry claimed he was given the chance to get close enough to the Queen to have poisoned her, and he took pictures of the monarch’s plastic breakfast containers, and the bed in which US President Bush and his wife Laura were to sleep.
The visit was also met with large protests over the Iraq War.
When the Queen encountered Mr Bush again, in Washington DC in 2007, the president winked at her after making a gaffe.
At a welcome ceremony on the south lawn of the White House, he mixed up his dates in a speech – almost ageing the Queen by 200 years.
Turning to the Queen and winking, he joked to his audience: “She gave me a look that only a mother could give a child.”
Mr Bush – in 2008 – was also received by the Queen at Windsor Castle.
The Queen’s relationship with Barack Obama was a warm and friendly one.
They hit it off after a reception ahead of the G20 summit in 2009.
The Queen and First Lady Michelle Obama acted like old friends when they put their arms around each other at the end of the event.
In her memoir, Becoming, Mrs Obama said they had just agreed that a long day wearing heels had left them with sore feet.
We were just “two tired ladies oppressed by our shoes”, she added.
A successful state visit to the UK followed in 2011 and the Obamas forged a strong bond with the Queen and her wider family – particularly Prince Harry, now the Duke of Sussex, and the Duke and Duchess of Cambridge.
The Obamas even dropped in to see the Queen the day after her 90th birthday.
The Duke of Edinburgh, then 94, drove the couple the short distance to Windsor Castle after their Marine One presidential helicopter touched down on the manicured lawns of the royal residence.
The Obamas also met Prince George, who was ready for bed in his dressing gown, ahead of dinner with William, Kate and Harry at Kensington Palace.
Mr Trump was accorded a guard of honour and had tea with the Queen at Windsor Castle in July 2018.
As the Queen and the president walked across the lawn of the quadrangle to view the troops, the monarch appeared to gesture and point several times for him to move closer to the front line of soldiers.
Mr Trump moved slightly nearer, but then stood still in front of the Queen, meaning the monarch had to navigate her way around him so they could walk side by side.
He later said of the sovereign in an interview: “That is a beautiful woman.”
The billionaire-turned-politician’s controversial state visit from June 3 to June 5 includes a ceremonial welcome at Buckingham Palace, lunch with the Queen and the Duke of Sussex, tea with the Prince of Wales and the Duchess of Cornwall at Clarence House, and a grand state banquet in the palace ballroom.