US President Donald Trump arrived at Windsor Castle on Wednesday, kicking off a two-day state visit to Britain as the guest of King Charles III.
The president's Marine One helicopter landed in the private Walled Garden at the Windsor estate.
Prince William and his wife Catherine, Princess of Wales were on hand to meet the president and first lady Melania Trump, walking them over to be greeted by the King and Queen Camilla.
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Carriages have been polished, hundreds of troops have been drilled to perfection, the family silver is being laid out, and diamonds are being dusted off for a day of royal pageantry on the president's unprecedented second state visit to Britain.
It's a spectacle with a purpose: to bolster ties with a world leader known for a love of bling at a time when his America First policies are putting pressure on trade and security arrangements globally.
Trump arrived in London late Tuesday and said he loved being back in the United Kingdom, calling it a "very special place."
Asked if he had a message for Charles, he said the King was a longtime friend of his and well-respected.
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The backdrop for day one is Windsor Castle, an almost 1000-year-old royal residence with gilded interiors, crenelated towers and priceless artworks.
A gigantic royal standard, the flag used for official celebration days, flew from the castle's Royal Tower as the king and queen prepared for the Trumps to arrive by helicopter from London, where they spent Tuesday night at the US ambassador's residence.
The prospect of a visit to the castle has seemed to enchant Trump, who ditched his trademark bluster and described the invitation as "a great, great honour."
"I think that also is why he seems so visibly excited about the second meeting, because it isn't an invitation given to (just) anyone," said George Gross, an expert on the British monarchy at King's College London.
The military ceremony to welcome Trump will be the largest one staged for a state visit to the UK in living memory, officials said.
In total, 120 horses and 1300 members of the British military will take part in the ceremonial welcome at Windsor.
The spectacle will conclude with a joint UK-US military flypast — a first during a state visit.
"The joint flypast by UK and US F-35 aircraft is a demonstration of the strength of the UK-US defense and security relationship," Britain's defense ministry said.
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