Capping off what has been an eventful two days, King Charles III and Queen Camilla were honored with a state dinner at the White House Tuesday night.

President Trump and the First Lady pulled out all of the stops for the first white-tie affair at the White House since the one that was thrown for the late Queen Elizabeth II by former president George W. Bush in 2007. Amazon‘s Jeff Bezos and his wife Lauren Sanchez, Apple’s chief executive officer Tim Cook and the fashion designer Ralph Lauren were among the guests at 1600 Pennsylvania Avenue. (FLOTUS had donned a white suit from Lauren’s namesake collection earlier Tuesday at the state arrival ceremony). Tuesday’s gathering is the fourth state dinner to have been held thus far during the two terms of the Trump administration.

Bezos and Sanchez will be soon be gathering for another grand gathering, as the lead sponsors of Monday’s Met Gala in New York City.

Perhaps as a gesture towards the guests of honor, FLOTUS chose a pale delphinium pink silk strapless gown from Christian Dior haute couture that was designed by the luxury house’s Northern Irish-born creative director Jonathan Anderson. Her evening ensemble included off-white Dior suede gloves and Dior pale delphinium pink pumps. The namesake founder of Christian Dior was such a gardening fan that that the house was reportedly nicknamed “the House of Flowers.” Delphinium is known to be one King Charles’ favorite flowers. So much so, that Highgrove collaborated with the artist Florence Super to create exclusive chinaware inspired by the long-stalk blooms.

Queen Camilla sported a long-sleeved hot pink Fiona Clare evening dress with a small clutch purse. Some might view the hue as “Millennial Pink.” Her accessory of choice was reportedly a diamond necklace that had been gifted by a former Duchess of Kent to Queen Victoria and was then passed to Queen Mary. King Charles and Donald Trump each were dressed for white tie in tails.

The Culture Concierge co-founder Alexandra Messervy, who once worked in the Royal Household of the late Queen Elizabeth II, said, “Much thought does go into dressing for any engagement and particularly for overseas tours. Outfits are planned well in advance and discussed with designers, with thought given to the occasion, the other guests, and often something pertinent about the country that is being visited.”

Those details can be seen in color choices such as the late Princess of Wales’ choice of a red and white outfit for a May 1986 visit to Japan for instance. While dress lengths and appropriate attire are always considered, other decisions are pragmatic like broad-brimmed hats that allow for faces easily seen and gloves to endure the many handshakes, Messervy said.

Earlier in the day, there was a state arrival ceremony with a 21-gun cannon salute for the most senior members of the British royal family on the White House grounds. His Majesty later became only the second British monarch to address a joint session of Congress. Stateside to commemorate the 250th anniversary of American independence, King Charles said, “For all that time, our destinies have been linked.”

Earlier Tuesday, FLOTUS and Queen Camilla took in a little artifical intelligence, by participating in a cross-cultural event with students including a few state champions from the Presidential AI Challenge.

Their Majesties were slated to spend Wednesday in New York City, where they planned to participate in a wreath-laying ceremony at the 9/11 Memorial. Afterwards, Queen Camilla was slated to tour the Treasures Collection at the New York Public Library and to present a replacement “Roo” stuffed animal to round out its “Winnie the Pooh” collection of toys. Those historic playthings once belonged to Christopher Robin Milne, whose father A.A. Milne drew inspiration from them to write the “Winnie the Pooh” books.

Once they return to Washington, D.C., there will be a sendoff by the Trumps at the White House Thursday, before King Charles and Queen Camilla head to Virginia for the final outing to wrap up their four-day U.S. stay.