Windsor Castle staff are setting the 50-meter long mahogany table.

Grooms are buffing the hooves of the horses that will pull the royal carriages.

And the military honor guard is drilling to insure every step lands with precision.

Throughout the halls and grounds of the almost 1,000-year-old castle west of London, hundreds of people are working to make sure King Charles III puts on the best show possible when he welcomes President Donald Trump for his historic second state visit this week.

The visit, featuring glittering tiaras, brass bands and a sumptuous banquet served on 200-year-old silver, is a display of the pomp and ceremony that Britain’s royal family does like no one else.

But it’s a spectacle with a purpose: to bolster ties with the most powerful man in the world at a time when his America First policies are roiling longstanding trade and security relationships.

"We’re buttering up to him," said Robert Lacey, a royal historian and consultant on the Netflix series "The Crown." "He wouldn’t come to Britain if he wouldn’t have the chance to stay at Windsor Castle, probably pay homage to the (late) queen he admires so much, and to meet the king."

Three centuries after Britain’s kings and queens gave up political power and settled for the role of ceremonial head of state, the royals remain a powerful instrument of "soft power," which the elected government uses to reward friends and wring concessions out of reluctant allies.

State visits are the monarchy’s ultimate tool, with world leaders vying to get the full royal treatment, including photographs with the king and the glamorous young royals, Prince William and Princess Catherine.

During seven decades on the throne, the late Queen Elizabeth II hosted everyone from Romanian dictator Nicolae Ceauşescu and Zairian strongman Mobutu Sese Seku to French President Charles De Gaulle and South African President Nelson Mandela.

Underscoring Britain’s "special relationship" with the U.S., Elizabeth welcomed each of the past three American presidents — George W. Bush in 2003, Barack Obama in 2011 and Trump in 2019.

Six years ago, Britain sought Trump’s support as it prepared to leave the European Union. This time the stakes may be even higher, with the U.K. lobbying for favorable trade terms and help combatting Russian aggression in Ukraine.

So Prime Minister Keir Starmer hurried to Washington in February, just five weeks after Trump began his second term, and handed him the king’s invitation for a state visit.

It was the first time any world leader received the honor of a second state visit, and the first time the invitation was delivered in a personal letter from the king, which Trump proudly displayed for the TV cameras.

And there will be plenty of glitz and glamor for a president who has gilded the Oval Office and plans to build a White House ballroom for 650 guests.

While the president and First Lady Melania Trump will arrive in the U.K. late Tuesday, the meat of the visit begins the next day when the king and Queen Camilla formally welcome the Trump’s to Windsor.

The notables will then climb into horse-drawn carriages for a ride through the Windsor estate and down a path to the castle lined by members of the armed forces.

Inside the crenellated stone-walls of the castle, which William the Conqueror started building in 1070, a military band will play the national anthems of both countries before Charles and Trump review the guard of honor in scarlet tunics and tall bearskin hats.

After the welcoming ceremonies, the Trumps will view an exhibit of historic documents and artwork put together to highlight the long shared history of Britain and the U.S.

The palace hasn’t said what will be on display, but the options are myriad for two countries with common legal and democratic traditions that stretch back to Magna Carta, the historic charter of rights signed in 1215 at Runnymede, just a few miles from Windsor.

But the centerpiece of the visit will be Wednesday night’s state banquet, where the men will don white ties and tail coats and the women will wear designer gowns and jewels that will sparkle in the flickering light from antique candelabra.

The king and queen will join their guests around the massive Waterloo Table, which is about half the length of a football field and has space for 160 guests. It takes five full days to set the table, which will be laid with the Grand Service, a silver-gilt dining service that includes more than 4,000 pieces ranging from serving dishes to dinner plates and egg cups.

"(Prime Minister) Keir Starmer has, cleverly in a way, used the king to lure President Trump over here, to give him a very good time," said Hugo Vickers, a royal historian and author of "Alice," a biography of the late Prince Philip’s mother.

"And (it’s) a wonderful opportunity, with all the goodwill that will be engaged at this point, to talk to him … and if there’s any hope of sorting out Ukraine, etc. this is all a step in the right direction."

Those discussions will take place Thursday, when Trump and Starmer meet at Chequers, the official country estate of British prime ministers.

AP Video by Kwiyeon Ha