And the military honour guard is drilling to ensure every step lands with precision.
Throughout the halls and grounds of the almost 1000-year-old castle west of London, hundreds of people are working to make sure King Charles puts on the best show possible when he welcomes US 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 does like no one else.
But it's a spectacle with a purpose: to bolster ties with one of the world's most powerful men at a time when his America First policies are roiling longstanding trade and security relationships.
State visits are the monarchy's ultimate tool, with world leaders vying to get the full royal treatment.
British Prime Minister Keir Starmer hurried to Washington in February and handed Trump the King's invitation for a state visit - the first time any world leader received the honour of a second state visit, and the first time the invitation was delivered in a personal letter from the King.
While the president and first lady Melania Trump will arrive in the UK late on Tuesday local time, the meat of the visit begins the next day.
After welcoming the Trumps, Charles and Queen Camilla will accompany them on a carriage ride through the Windsor estate, then back to the castle along a path lined by members of the armed forces.
Inside the crenellated 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 honour in scarlet tunics and tall bearskin hats.
But the centrepiece 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 tiaras will be out in force,'' said Hugo Vickers, a royal historian and author of Alice, a biography of the late Prince Philip's mother. "It will all look very splendid."
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 4000 pieces ranging from serving dishes to dinner plates and egg cups.
"Keir Starmer has, cleverly in a way, used the King to lure President Trump over here, to give him a very good time," Vickers said.
"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 take place on Thursday, local time, when Trump and Starmer meet at Chequers, the country estate of British prime ministers.
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